Astronomy Picture of the Day |
APOD: 2024 August 7 – Milky Way Behind Three Merlons
Explanation:
To some, they look like battlements,
here protecting us against the center of the
Milky Way.
The Three
Merlons,
also called the
Three Peaks of Lavaredo, stand tall today because they are made of dense dolomite rock which has better resisted
erosion
than surrounding softer rock.
They formed about
250 million years ago and so are comparable in age with one of the
great extinctions of life on
Earth.
A leading hypothesis is that this great
extinction
was triggered by an
asteroid about 10-km across, larger in size than
Mount Everest, impacting the Earth.
Humans have gazed up at the stars in the
Milky Way and beyond for centuries,
making these battlefield-like formations, based in the
Sexten Dolomites, a popular place for
current and
ancient astronomers.
APOD: 2024 August 5 – Milky Way Over Tunisia
Explanation:
That's
no moon.
On the ground, that's the
Lars Homestead in
Tunisia.
And that's not just any galaxy.
That's the central band of our own
Milky Way galaxy.
Last, that's not just any meteor.
It is a bright
fireball likely from last year's
Perseids meteor shower.
The
featured image composite combines consecutive exposures
taken by the same camera from the same location.
This year's Perseids
peak during the coming weekend is
expected to show the most meteors after the
first quarter moon sets, near midnight.
To best experience a meteor shower,
you should have clear and dark skies, a
comfortable seat, and patience.
APOD: 2024 July 29 – Milky Way over Uluru
Explanation:
What's happening above Uluru?
A United Nations World Heritage Site,
Uluru
is an extraordinary 350-meter high mountain in central
Australia
that rises sharply from nearly flat surroundings.
Composed of sandstone, Uluru has
slowly formed over the past 300 million years
as softer rock eroded away.
The Uluru region has been a
home to humans for
over 22,000 years.
Recorded
last month, the starry sky above
Uluru
includes the central band of our
Milky Way galaxy, complete with complex dark filaments of
dust, bright red
emission
nebulas, and
billions of stars.
APOD: 2024 July 21 – King of Wings Hoodoo under the Milky Way
Explanation:
This rock structure is not only surreal -- it's real.
Perhaps the reason it's not more famous is that it is
smaller than one might guess: the capstone rock overhangs only a
few meters.
Even so, the
King of Wings outcrop, located in
New Mexico,
USA, is a fascinating example of an unusual type of rock structure called a
hoodoo.
Hoodoos may
form when a layer of hard rock overlays a layer of
eroding
softer rock.
Figuring out the details of incorporating
this hoodoo
into a night-sky photoshoot took over a year.
Besides
waiting for a suitably picturesque night
behind a sky with few clouds, the foreground had to be
artificially lit
just right relative to the
natural glow of the background.
After much planning and waiting, the final shot,
featured here,
was taken in May 2016.
Mimicking the horizontal bar, the background sky features the band of our
Milky Way Galaxy stretching overhead.
APOD: 2024 July 5 - Mount Etna Milky Way
Explanation:
A glow from the summit of
Mount Etna,
famous active stratovolcano of planet Earth,
stands out along the horizon in this
mountain and night
skyscape.
Bands of diffuse light from
congeries
of innumerable stars
along the Milky Way galaxy stretch across the sky above.
In silhouette, the Milky Way's massive dust clouds are clumped along
the galactic plane.
Also familiar to northern skygazers are bright
stars Deneb, Vega, and Altair,
the Summer Triangle
straddling dark nebulae and
luminous star clouds poised over the volcanic peak.
The deep combined exposures reveal the light of active
star forming
regions along the Milky Way,
echoing Etna's
ruddy hue
in the northern hemisphere
summer's night.
APOD: 2024 June 26 – Timelapse: Aurora, SAR, and the Milky Way
Explanation:
What's happening in the sky this unusual night?
Most striking in the featured 4.5-hour 360-degree
panoramic video, perhaps, is the pink and purple
aurora.
That's because this night, encompassing May 11, was famous for its
auroral skies around the world.
As the night progresses,
auroral bands shimmer, the
central band of our
Milky Way Galaxy rises, and
stars shift as the
Earth rotates beneath them.
Captured here simultaneously is a rare red band running above the aurora: a
SAR arc, seen to change only slightly.
The flashing below the horizon is caused by passing cars, while the moving spots in the sky are satellites and airplanes.
The featured video was captured from
Xinjiang,
China with four separate cameras.
APOD: 2024 May 29 – Stairway to the Milky Way
Explanation:
What happens if you ascend this
stairway to the Milky Way?
Before answering that, let's understand the beautiful sky you will see.
Most eye-catching is the grand arch of the
Milky Way Galaxy, the
band that is the
central disk of our galaxy which is
straight
but distorted by the wide-angle nature of
this composite image.
Many stars well in front of the Milk Way will be visible,
with the bright white star just below the
stellar arch being
Altair,
and the bright blue star above it being
Vega.
The air glows green on the left,
just above the yellow cloud deck.
The featured image was taken last month on
Portugal's
Madeira Island in the North
Atlantic Ocean.
Oh, and what happens after you reach the
top of these stairs and
admire the amazing sky is,
quite probably, that you then
descend down the stairs
on the other side.
APOD: 2024 March 16 - ELT and the Milky Way
Explanation:
The southern winter
Milky Way sprawls
across this night skyscape.
Looking due south, the
webcam view
was recorded near local midnight
on March 11 in dry, dark skies over the central Chilean Atacama desert.
Seen below the graceful arc of diffuse starlight
are satellite galaxies of the mighty Milky Way, also known as
the Large and Small
Magellanic clouds.
In the foreground is the site of the European Southern
Observatory's 40-metre-class
Extremely Large Telescope
(ELT).
Under construction at the 3000 metre summit of
Cerro Armazones, the ELT is
on track to become planet Earth's biggest Eye on the Sky.
APOD: 2023 December 12 – Aurora and Milky Way over Norway
Explanation:
What are these two giant arches across the sky?
Perhaps the more familiar one, on the left, is the central band of our
Milky Way Galaxy.
This grand disk of stars and nebulas here appears to encircle much of the southern sky.
Visible below the stellar arch is the
rusty-orange planet
Mars and the extended
Andromeda galaxy.
But this night had more!
For a few minutes during this
cold
arctic night, a second
giant arch appeared
encircling part of the northern sky: an
aurora.
Auroras are much closer than stars as they are composed of glowing air high in
Earth's atmosphere.
Visible outside the
green auroral arch is the group of stars popularly
known as the
Big Dipper.
The featured digital composite of 20 images was captured in
mid-November 2022 over the
Lofoten Islands in
Norway.
APOD: 2023 December 1 - Milky Way Rising
Explanation:
The core of the Milky Way
is rising beyond the Chilean mountain-top
La Silla
Observatory in this
deep night skyscape.
Seen toward the constellation Sagittarius, our home galaxy's center
is flanked on the left, by the European Southern Observatory's New
Technology Telescope which pioneered the use of active optics to
accurately control the shape of large telescope mirrors.
To the right stands the ESO 3.6-meter Telescope,
home of the exoplanet hunting
HARPS
and
NIRPS
spectrographs.
Between them, the
galaxy's central bulge
is filled with obscuring
clouds of interstellar dust, bright stars,
clusters, and nebulae.
Prominent reddish hydrogen emission from the star-forming
Lagoon Nebula, M8, is near center.
The Trifid Nebula, M20, combines blue light of a dusty reflection nebula
with reddish emission just left of the cosmic Lagoon.
Both are popular
stops on telescopic tours of the galactic center.
The composited image
is a stack of separate exposures for ground
and sky made in April 2023, all captured consecutively
with the same framing and camera equipment.
APOD: 2023 September 27 – STEVE and Milky Way Cross over Rural Road
Explanation:
Not every road ends in a STEVE.
A week ago, a sky enthusiast's journey began with a goal:
to photograph an
aurora over
Lake Huron.
Driving through rural
Ontario,
Canada,
the forecasted sky show started
unexpectedly early,
causing the photographer to stop before arriving at the scenic
Great Lake.
Aurora images were taken toward the north -- but over land, not sea.
While waiting for a second round of auroras, a
peculiar band of light was noticed to the west.
Slowly, the photographer and friends realized
that this western band was likely an unusual type of aurora: a
Strong Thermal Emission Velocity Enhancement (STEVE).
Moreover, this
STEVE was putting on quite a show:
appearing intertwined with the central band of our
Milky Way Galaxy while intersecting the horizon just
near the end of the country road.
After capturing
this cosmic X
on camera, the photographer paused to appreciate the
unexpected awesomeness of finding
extraordinary beauty in an ordinary setting.
APOD: 2023 August 24 - Meteors along the Milky Way
Explanation:
Under dark
and mostly moonless night skies, many
denizens of planet Earth
were able to watch this year's Perseid meteor shower.
Seen from a grassy hillside from Shiraz, Iran these
Perseid meteors streak
along the northern summer Milky Way
before dawn on Sunday, August 13.
Frames used to construct the composited image
were captured near the
active annual meteor shower's peak
between 02:00 AM and 04:30 AM local time.
Not in this night skyscape, the shower's radiant in
the heroic constellation Perseus is far above the camera's field
of view.
But fans of northern summer nights
can still spot
a familiar asterism.
Formed by bright stars Deneb, Vega, and Altair, the
Summer Triangle
spans the luminous band of the Milky Way.
APOD: 2023 July 18 – Milky Way above La Palma Observatory
Explanation:
What's happening in the night sky?
To help find out, telescopes all over the globe will be
pointing into deep space.
Investigations will include trying to understand the
early universe, finding and tracking
Earth-menacing asteroids,
searching for
planets that might contain extra-terrestrial life,
and
monitoring stars to help better understand our Sun.
The
featured composite includes foreground and background images taken in April
from a mountaintop on
La Palma island in the
Canary Islands of
Spain.
Pictured, several telescopes from the
Roque de los Muchachos Observatory
are shown in front of a dark night sky.
Telescopes in the foreground include, left to right,
Magic 1,
Galileo,
Magic 2,
Gran Telescopio Canarias, and
LST.
Sky highlights in the background include the
central band of our
Milky Way Galaxy, the constellations of
Sagittarius,
Ophiuchus and
Scorpius, the red-glowing
Eagle and
Lagoon Nebulas, and the stars
Alrami and
Antares.
Due to observatories
like this, humanity has understood more about our
night sky
in the past 100 years than ever before in all of
human history.
APOD: 2023 July 16 – Meteor and Milky Way over the Alps
Explanation:
Now this was a view with a thrill.
From
Mount Tschirgant
in the
Alps,
you can see not only nearby towns and distant
Tyrolean peaks,
but also, weather permitting, stars, nebulas, and the band of the
Milky Way Galaxy.
What made the
arduous climb worthwhile this night,
though, was another peak -- the peak of the 2018
Perseids
Meteor
Shower.
As hoped, dispersing clouds allowed a picturesque sky-gazing session that included
many faint
meteors,
all while a carefully positioned camera took a series of exposures.
Suddenly, a thrilling meteor --
bright and
colorful -- slashed down right next to the nearly
vertical band of the Milky Way.
As luck would have it, the camera caught it too.
Therefore, a new image in the series was quickly taken with one of the
sky-gazers posing on the nearby peak.
Later, all of the images were digitally combined.
APOD: 2023 July 2 – Milky Way and Aurora over Antarctica
Explanation:
It was one of the better skies of this long night.
In parts of
Antarctica, not only is it winter, but the Sun can spend weeks below the horizon.
At
China's
Zhongshan Station,
people sometimes venture out into the cold to photograph a spectacular night sky.
The featured image from one such outing was taken in mid-July of 2015,
just before the end of this
polar night.
Pointing up, the
wide angle lens
captured not only the ground at the bottom, but at the top as well.
In the foreground, a colleague is taking pictures.
In the distance, a spherical satellite receiver and several
windmills
are visible.
Numerous stars dot the night sky, including
Sirius and
Canopus.
Far in the background,
stretching overhead from horizon to horizon, is the
central band of our
Milky Way Galaxy.
Even further in the distance, visible as extended smudges near the top, are the
Large and
Small Magellanic
Clouds, satellite galaxies near our huge
Milky Way Galaxy.
APOD: 2023 June 20 – The Nandu in the Milky Way
Explanation:
Have you seen the bird in the Milky Way?
Beyond the
man in the Moon, the night sky is filled with stories,
and cultures throughout history have projected some of their most
enduring legends onto the stars and dust above.
Generations of people see these celestial icons,
hear their associated stories, and pass them down.
Pictured here is not only a segment of the
central band of our
Milky Way galaxy, but, according to
folklore of several native peoples of
Uruguay,
the outline of a great bird called
Ñandú.
Furthermore, Ñandú's footprint is associated with the
Southern
Cross asterism.
In the foreground, in
silhouette, is a statue of
MarÃa Micaela Guyunusa, an indigenous woman of the
Charrúa
people who lived in the 1800s and endures as a symbol of colonial resistance.
The composite image was taken in mid-April in
Cabo Polonio,
Uruguay, with the
Atlantic Ocean in the background.
APOD: 2023 May 29 – Milky Way over a Turquoise Wonderland
Explanation:
What glows there?
The answer depends: sea or sky?
In the sea, the unusual blue glow is
bioluminescence.
Specifically, the glimmer arises from
Noctiluca scintillans, single-celled plankton stimulated by the lapping waves.
The plankton
use their glow to
startle and illuminate predators.
This mid-February display on an island in the
Maldives was so intense that the astrophotographer described it as a
turquoise wonderland.
In the sky, by contrast, are the more familiar glows of
stars and
nebulas.
The white band rising from the artificially-illuminated
green plants is created by billions of stars in the
central disk of our
Milky Way Galaxy.
Also visible in the sky is the star cluster
Omega Centauri, toward the left, and the famous
Southern Cross
asterism in the center.
Red-glowing nebulas include the bright
Carina Nebula, just right of center, and the expansive
Gum Nebula on the upper right.
APOD: 2023 February 20 – NGC 1850: Not Found in the Milky Way
Explanation:
There is nothing like this ball of stars in our Milky Way Galaxy.
This is surprising because, at first glance, this
featured image by the
Hubble Space Telescope suggests that star cluster
NGC 1850's
size and shape are reminiscent of the many
ancient globular
star clusters
which roam our own
Milky Way Galaxy's halo.
But NGC 1850's stars are all too young, making it a type of star cluster with
no known counterpart in the Milky Way.
Moreover, NGC 1850 is also a
double star cluster, with a second, compact cluster of stars visible here just to the right of the large cluster's center.
Stars in the large cluster are estimated to be 50 million years young,
while stars in the compact cluster are younger still, with an age of about 4 million years.
A mere 168,000 light-years distant, NGC 1850 is located near the outskirts of the
Large Magellanic Cloud galaxy.
The glowing gas filaments across the image left, like
supernova remnants in our own galaxy,
testify to violent
stellar explosions
and indicate that short-lived massive
stars have recently been present in the region.
APOD: 2022 October 23 - Milky Way and Zodiacal Light over Australian Pinnacles
Explanation:
What strange world is this?
Earth.
In the foreground of the featured image are the Pinnacles,
unusual rock spires in
Nambung National Park in Western
Australia.
Made of ancient sea shells
(limestone), how these human-sized
picturesque spires formed remains a
topic of research.
The picturesque panorama was taken in 2017 September.
A ray of
zodiacal light,
sunlight reflected by dust grains orbiting between the planets in the
Solar System,
rises from the horizon near the image center.
Arching across the top is the central band of our
Milky Way Galaxy.
The planets
Jupiter and
Saturn,
as well as several famous
stars are also visible in the background night sky.
APOD: 2022 October 18 - Milky Way Auroral Flower
Explanation:
Could the stem of our Milky Way bloom into an auroral flower?
No, not really, even though it may appear that way in
today’s featured all-sky image.
On the left, the
central plane of our
home galaxy
extends from the horizon past the
middle of the sky.
On the right, an
auroral oval also extends from the sky's center --
but is dominated by bright
green-glowing oxygen.
The two are not physically connected, because the
aurora is relatively nearby, with the
higher red parts occurring in
Earth's atmosphere only about 1000
kilometers high.
In contrast, an average distance to the
stars and nebulas we see in the
Milky Way more like 1000 light-years away - 10 trillion times further.
The featured image
composite was taken in early October across a small lake in
Abisko, northern
Sweden.
As our
Sun's magnetic field evolves into the active part of its
11-year cycle,
auroras near both of Earth's poles are
sure to become
more frequent.
APOD: 2022 August 23 - Meteor and Milky Way over the Mediterranean
Explanation:
Careful planning made this a nightscape to remember.
First, the night itself was chosen to occur during the beginning of this year's
Perseid Meteor Shower.
Next, the time of night was chosen to be before the
bright Moon would rise and
dominate the
night sky's brightness.
The picturesque foreground was selected to be a rocky beach of the
Mediterranean Sea in
Le Dramont,
France, with, at the time,
île d’Or
island
situated near the ominously descending central band of our
Milky Way
Galaxy.
Once everything was set and with the weather cooperating, all of the frames for
this seemingly surreal nightscape were acquired within 15 minutes.
What you can't see is that, on this night,
the astrophotographer brought along his father who,
although unskilled in modern sky-capture techniques,
once made it a point to
teach his child about the sky.
APOD: 2022 August 17 - Stargate Milky Way
Explanation:
There is a huge gate of stars in the sky, and you pass through it twice a day.
The stargate is actually our
Milky Way Galaxy, and it is the spin of the Earth that appears to propel you through it.
More typically, the
central band of our
Milky Way appears as a faint band stretching across the sky,
only visible in away from
bright city lights.
In a long-exposure wide-angle image from a
dark location
like this, though, the Milky Way's central plane is
easily visible.
The featured picture
is a digital composite involving multiple exposures
taken on the same night and with the same camera, but employing a
stereographic projection
that causes the Milky Way to appear as a
giant circular portal.
Inside the
stargate-like arc of
our Galaxy
is a faint stripe called
zodiacal light -- sunlight reflected by
dust in our
Solar System.
In the foreground are
cacti
and dry rocks found in the rough terrain of the high desert of
Chile, not far from the
El Sauce
Observatory and the developing
Vera Rubin Observatory, the latter expected to
begin routine operations in 2024.
APOD: 2022 July 6 - Milky Way Motion in 3D from Gaia
Explanation:
Our sky is alive with the streams of stars.
The motions of 26 million
Milky Way stars are evident in the
featured map constructed from recent data taken by
ESA's
Gaia satellite.
Stars colored blue are
moving toward us, while red indicates away.
Lines depict the
motion of the stars across the sky.
The large blue areas on the left and red areas on
the map's right give the overall impression
that stars in the Milky Way are
rotating around the center.
Understanding details about the
motion of stars is
helping humanity to better understand the
complex history of our
Milky Way galaxy
and the origin of
our Sun.
APOD: 2022 June 11 - The Road and the Milky Way
Explanation:
At night you can follow this road as it
passes through the Dark Sky Alqueva reserve not too
far from Alentejo, Portugal.
Or you could stop,
look up,
and follow the Milky Way through the sky.
Both stretch from
horizon to horizon in this
180 degree panorama
recorded on June 3.
Our galaxy's name, the Milky Way, does
refer to its appearance as a milky path in the sky.
The word galaxy itself derives from the Greek for milk.
From our fair planet
the arc of the Milky Way is most easily visible on moonless nights
from dark sky areas, though not quite so bright or colorful as in this image.
The glowing celestial band is due to the collective light of
myriad stars along the galactic plane too faint to be
distinguished individually.
The diffuse starlight is cut by dark swaths
of the galaxy's obscuring interstellar dust clouds.
Standing above the Milky Way arc near the top of this
panoramic nightscape is
bright star Vega, with the galaxy's
central bulge
near the horizon at the right.
APOD: 2022 June 6 - Milky Way Galaxy Doomed: Collision with Andromeda Pending
Explanation:
Will our Milky Way Galaxy collide one day with its larger neighbor, the Andromeda Galaxy?
Most likely, yes.
Careful plotting of slight displacements of M31's stars
relative to background galaxies on recent
Hubble Space Telescope images indicate that the center of M31 could be on a direct
collision course with the center of our home
galaxy.
Still, the errors in sideways velocity appear sufficiently large to admit a
good chance that the central parts of the two galaxies will miss, slightly, but will become
close enough for their outer halos to become gravitationally
entangled.
Once that happens, the two galaxies will become bound,
dance around, and
eventually merge to
become one large
elliptical galaxy --
over the next few billion years.
Pictured here is a combination of images depicting
the sky of a world (Earth?) in the distant future when the outer parts of each galaxy
begin to collide.
The exact future of our Milky Way and the entire surrounding
Local Group of Galaxies
is likely to remain an active
topic of research for years to come.
APOD: 2022 May 16 - Milky Way over French Alp Hoodoos
Explanation:
Real castles aren't this old.
And the background galaxy is even older.
Looking a bit like an alien castle, the pictured rock spires are called
hoodoos and are likely millions of years old.
Rare, but found around the world,
hoodoos
form when dense rocks slow the
erosion of
softer rock underneath.
The
pictured hoodoos survive in the
French Alps and are named
Demoiselles
Coiffées -- which translates to English as
"Ladies with Hairdos".
The background galaxy is part of the central disk of our own
Milky Way galaxy and contains
stars that are typically billions of years old.
The photogenic
Cygnus sky region -- rich in
dusty
dark clouds and red
glowing nebulas --
appears just above and behind the hoodoos.
The featured image
was taken in two stages: the foreground was captured during the evening
blue hour,
while the background was acquired from the same location later that night.
APOD: 2022 May 13 - The Milky Way's Black Hole
Explanation:
There's a black hole
at the center of the Milky Way.
Stars are observed to orbit
a very massive and
compact object
there known as Sgr A* (say "sadge-ay-star").
But this just released radio image (inset) from planet Earth's
Event Horizon Telescope is the
first direct evidence of the Milky Way's central black hole.
As predicted by Einstein's Theory of General Relativity,
the four million solar mass black hole's strong gravity
is bending light and creating a shadow-like dark central region
surrounded by a bright ring-like structure.
Supporting observations made by
space-based telescopes and ground-based observatories
provide a wider view of the galactic center's dynamic environment
and an important
context for the Event Horizon Telescope's black hole image.
The main panel image
shows the X-ray data from Chandra and infrared data from Hubble.
While the main panel is about 7 light-years across,
the Event Horizon Telescope inset image itself spans a mere 10
light-minutes
at the center of our galaxy,
some 27,000 light-years away.
APOD: 2022 April 13 - Milky Way over Devils Tower
Explanation:
What created Devils Tower?
The origin of this
extraordinary rock monolith in
Wyoming,
USA is still debated,
with a leading hypothesis holding that it is a
hardened lava plume that never reached the surface to become a volcano.
In this theory, the lighter rock that once surrounded the
dense volcanic neck has now eroded away, leaving
the dramatic tower.
Known by Native Americans by names including
Bear's Lodge
and Great Gray Horn,
the dense rock includes the longest
hexagonal
columns known, some over 180-meters tall.
High above, the
central band of the
Milky Way galaxy arches across the sky.
Many notable sky objects are visible, including dark strands of the
Pipe Nebula and the
reddish Lagoon Nebula to the tower's right.
Green grass and trees line
the foreground,
while clouds appear near the horizon to the tower's left.
Unlike many other international landmarks, mountaineers are permitted to
climb Devils Tower.
APOD: 2022 March 12 - Point Reyes Milky Way
Explanation:
Northern winter
constellations and a long arc of the Milky Way
are setting in this night skyscape looking toward the Pacific Ocean from
Point Reyes on
planet Earth's
California coast.
Sirius, alpha star of Canis Major, is prominent below the starry arc
toward the left.
Orion's yellowish
Betelgeuse, Aldebaran in Taurus, and the blue tinted
Pleiades star cluster
also find themselves between
Milky Way and northwestern horizon near the center of the scene.
The nebulae visible in the series of exposures used to construct
this panoramic view were captured in early March,
but are just too faint to be seen with the unaided eye.
On that northern night their
expansive glow includes
the reddish semi-circle of Barnard's Loop
in Orion and
NGC 1499 above and right of the Pleiades, also known as the
California Nebula.
APOD: 2021 December 21 - Solstice Sun and Milky Way
Explanation:
Welcome to December's solstice, first day of winter in the north and
summer for the southern hemisphere.
Astronomical markers of the seasons,
solstice and equinox
dates are based on the Sun's place in its annual journey along the ecliptic, through planet Earth's sky.
At this solstice,
the Sun reaches its maximum southern
declination
of -23.5 degrees today at 15:59
UTC, while its
right ascension
coordinate on the
celestial sphere
is 18 hours.
That puts the Sun in the
constellation Sagittarius in a direction near
the center of our Milky Way galaxy.
In fact, if you could see today's
Solstice Sun
against faint background stars and nebulae (that's
really hard to do, especially in the daytime ...)
your view might look something like this composited panorama.
To make it, images of
our fair galaxy
were taken under dark
Namibian
night skies, then stitched together in a panoramic view.
From a snapshot made on
2015 December 21,
the Sun was digitally overlayed as a brilliant star at today's northern winter
solstice position, close to the center of the Milky Way.
APOD: 2021 November 1 - A Waterfall and the Milky Way
Explanation:
The dream was to capture both the waterfall and the Milky Way together.
Difficulties included finding a good camera location, artificially illuminating the waterfall and the surrounding valley effectively, capturing the entire scene with numerous foreground and background shots, worrying that
fireflies would be too
distracting, keeping the camera dry,
and avoiding stepping on a poisonous snake.
Behold the result -- captured after midnight in
mid-July and digitally stitched into a wide-angle panorama.
The waterfall is the picturesque
Zhulian waterfall in the
Luoxiao Mountains in eastern
Hunan Province,
China.
The central band of our
Milky Way Galaxy crosses the sky and shows numerous
dark dust filaments and
colorful nebulas.
Bright stars dot the sky -- all residing in the nearby Milky Way -- including the
Summer Triangle with bright
Vega visible above the
Milky Way's arch.
After capturing all 78 component exposures for you to enjoy,
the photographer and friends
enjoyed the view themselves
for the rest of the night.
APOD: 2021 October 1 - The Central Milky Way from Lagoon to Pipe
Explanation:
Dark markings and colorful clouds
inhabit this stellar landscape.
The deep and expansive view spans more than 30 full moons across
crowded star fields toward the center of our Milky Way Galaxy.
Cataloged in
the early 20th century by astronomer
E. E. Barnard,
the obscuring interstellar dust clouds seen toward the right
include B59, B72, B77 and B78,
part of the Ophiuchus molecular cloud complex a mere 450 light-years away.
To the eye their combined shape
suggests a pipe
stem and bowl, and so the dark nebula's popular name is
the Pipe Nebula.
Three bright nebulae gathered on the left are
stellar nurseries some 5,000 light-years distant toward
the constellation Sagittarius.
In the 18th century astronomer
Charles Messier included
two of them in his catalog of bright clusters and nebulae; M8, the
largest of the triplet,
and colorful M20 just above.
The third prominent emission region includes NGC 6559 at the far left.
Itself divided by obscuring dust lanes, M20 is also known as
the Trifid.
M8's popular moniker is
the Lagoon Nebula.
APOD: 2021 September 6 - Firefly Milky Way over Russia
Explanation:
It started with a pine tree.
The idea was to photograph a statuesque
pine
in front of the central band of our
Milky Way Galaxy.
And the plan, carried out two months ago, was successful --
they both appear prominently.
But the resulting 3-frame panorama captured much more.
Colorful stars,
for example, dot the distant background, with bright
Altair visible on the upper left.
The planet Saturn, a bit closer, was captured just over the horizon on the far left.
Just beyond the
Earth's atmosphere, seen in the upper right, an
Earth-orbiting satellite
was caught leaving a streak during the 25-second exposure.
The Earth's atmosphere itself was
surprisingly visible -- as
green airglow
across the image top.
Finally, just by chance, there was a
firefly.
Do you see it?
Near the image bottom,
the firefly blinked in yellow several times as it
fluttered before the rolling hills above
Milogradovka River in
Primorsky Krai,
Russia.
APOD: 2021 August 3 - A Perseid Meteor and the Milky Way
Explanation:
It was bright and green and flashed as it moved quickly along the Milky Way.
It left
a trail that took 30 minutes to dissipate.
Given the day, August 12, and the direction, away
from Perseus,
it was likely a small bit from the nucleus of
Comet Swift-Tuttle plowing through the
Earth's atmosphere -- and therefore part of the annual
Perseids meteor shower.
The astrophotographer captured the fireball
as it shot across the sky in 2018 above a valley in
Yichang, Hubei,
China.
The meteor's streak, also caught
on video,
ended near the
direction of Mars on the lower left.
Next week, the 2021 Perseids meteor shower will peak again.
This year
the Moon will set shortly after
the Sun, leaving a night sky ideal for seeing
lots of Perseids from dark and clear locations across
planet Earth.
APOD: 2021 July 3 - Along the Milky Way
Explanation:
You can't
walk along the Milky Way.
Still, under a dark sky
you can explore it.
To the eye the pale luminous trail of light arcing
through the sky on a dark, moonless night does appear to be
a path through the heavens.
The glowing celestial band is the faint,
collective
light of distant stars
cut by swaths of obscuring interstellar dust clouds.
It lies along the plane of
our home galaxy,
so named because it looks like a milky way.
Since Galileo's time, the Milky Way has been revealed
to telescopic skygazers to be filled with
congeries of innumerable stars
and
cosmic wonders.
APOD: 2021 May 27 - Mid-Eclipse and Milky Way
Explanation:
May's perigee Full Moon
slid through Earth's shadow yesterday
entertaining night skygazers in regions
around the Pacific.
Seen from western North America, it
sinks toward the rugged Sierra Nevada mountain range in this
time-lapse series of the total lunar eclipse.
Low on the western horizon the Moon was captured at
mid-eclipse with two separate exposures.
Combined they reveal the
eclipsed Moon's reddened color
against the dark night sky
and the diffuse starlight band of the Milky Way.
Frames taken every five minutes from the fixed camera follow the
surrounding progression of the eclipse partial phases.
In the foreground a radio telescope dish at California's
Owens Valley Radio Observatory
points skyward.
APOD: 2020 November 17 - A Glowing STEVE and the Milky Way
Explanation:
What's creating these long glowing streaks in the sky?
No one is sure.
Known as
Strong Thermal Emission Velocity Enhancements (STEVEs),
these luminous light-purple sky ribbons may resemble
regular auroras,
but recent research reveals significant differences.
A STEVE's great length and unusual colors, when measured precisely,
indicate that it may be related to a
subauroral ion drift (SAID),
a supersonic river of hot atmospheric
ions thought previously to be
invisible.
Some STEVEs are
now also thought to be accompanied by
green picket fence structures, a series of
sky slats that can appear outside of the main
auroral oval that
does not involve much glowing
nitrogen.
The featured wide-angle composite
image shows a STEVE in a dark sky above
Childs Lake,
Manitoba,
Canada in 2017,
crossing in front of the central band of our
Milky Way Galaxy.
APOD: 2020 October 11 - Milky Way over the Pinnacles in Australia
Explanation:
What strange world is this?
Earth.
In the foreground of the featured image are the
Pinnacles,
unusual rock spires in
Nambung National Park in Western
Australia.
Made of ancient sea shells
(limestone), how these human-sized
picturesque spires formed remains unknown.
In the background, just past the end of the central Pinnacle, is a bright crescent Moon.
The eerie glow around the Moon is mostly
zodiacal light,
sunlight reflected by dust grains orbiting between the planets in the
Solar System.
Arching across the top is the central band of our
Milky Way Galaxy.
Many famous
stars and
nebulas are also visible in the background night sky.
The featured 29-panel panorama was taken and composed in
2015 September after detailed planning that involved the Moon,
the rock spires, and their corresponding
shadows.
Even so, the strong zodiacal light was a pleasant
surprise.
APOD: 2020 September 7 - The Milky Way over St Michaels Mount
Explanation:
Where do land and sky converge?
On every
horizon -- but in this case the path on the ground leads to
St Michael's Mount (Cornish: Karrek Loos yn Koos),
a small historic island in
Cornwall,
England.
The Mount is usually surrounded by shallow water, but at low
tide is spanned by a human-constructed causeway.
The path on the sky, actually the central band of our
Milky Way Galaxy, also appears to lead to
St Michael's Mount,
but really lies far in the distance.
The red nebula in the Milky Way, just above the
castle,
is the Lagoon Nebula, while bright
Jupiter shines to the left, and a luminous
meteor flashes to the right.
The foreground and background images of
this featured composite were taken on the same July night and from the same location.
Although meteors are fleeting and the
Milky Way disk shifts in the night
as the Earth turns, Jupiter will remain
prominent in the sunset sky
into December.
APOD: 2020 August 17 - Perseids Around the Milky Way
Explanation:
Why would meteor trails appear curved?
The arcing effect arises only because the image
artificially compresses (nearly) the whole sky
into a rectangle.
The meteors are from the
Perseid Meteor Shower that peaked last week.
The featured multi-frame image combines not only
different directions from the 360 projection, but different times when
bright Perseid meteors momentarily streaked across the sky.
All Perseid meteors can be traced back to the
constellation Perseus
toward the lower left, even the seemingly curved (but really straight)
meteor trails.
Although Perseids always point back to their
Perseus radiant, they can appear almost anywhere on the sky.
The image was taken from
Inner Mongolia,
China, where
grasslands meet
sand dunes.
Many treasures also visible in the busy night sky including the
central arch of our
Milky Way Galaxy, the planets
Saturn and Jupiter toward the right,
colorful airglow on the central left,
and some relatively nearby Earthly clouds.
The Perseid Meteor Shower peaks every August.
APOD: 2020 June 17 - Magnetic Streamlines of the Milky Way
Explanation:
What role do magnetic fields play in interstellar physics?
Analyses of observations by ESA's
Planck satellite
of emission by small magnetically-aligned dust grains reveal previously unknown
magnetic field
structures in our
Milky Way Galaxy -- as shown by the curvy lines in the
featured full-sky image.
The dark red shows the
plane of the Milky Way,
where the concentration of dust is the highest.
The huge arches above the plane are likely remnants of
past explosive events from
our Galaxy's core, conceptually similar to magnetic
loop-like structures seen in our Sun's atmosphere.
The curvy streamlines align with
interstellar filaments of neutral hydrogen gas and provide tantalizing evidence that magnetic fields may supplement gravity in not only in shaping the
interstellar medium,
but in forming stars.
How magnetism
affected our
Galaxy's evolution
will likely remain a
topic of research for years to come.
APOD: 2020 May 26 - The Milky Way over Snow Capped Himalayas
Explanation:
What’s higher than the Himalayas?
Although the
Himalayan Mountains
are the tallest on planet Earth, they don't measure up to the
Milky Way.
Visible above the snow-capped mountains in the featured image is the
arcing central band of our home galaxy.
The bright spot just above the central plane is the
planet Jupiter,
while the brightest orange spot on the upper right is the
star Antares.
The astrophotographer
braved below-zero temperatures at nearly 4,000-meters
altitude to take the photographs that compose this image.
The featured picture is a composite of eight exposures
taken with same camera and from the same location over three hours,
just after sunset, in 2019 April, from
near Bimtang Lake in
Nepal.
Over much of
planet Earth, the planets
Mercury (faint) and
Venus (bright) will be
visible this week after sunset.
APOD: 2020 May 20 - Moon, Mars, Saturn, Jupiter, Milky Way
Explanation:
It is not a coincidence that planets line up.
That's because all of the
planets orbit the
Sun in (nearly)
a single sheet called the plane of the
ecliptic.
When viewed from inside that plane -- as
Earth dwellers are likely to do --
the planets all appear confined to a
single band.
It is a coincidence, though, when
three of the brightest planets all appear in nearly the same direction.
Such a coincidence was captured about a month ago.
Featured above,
Earth's Moon,
Mars,
Saturn, and
Jupiter were all
imaged together,
just before sunrise, from the
Black Sea coast of
Bulgaria.
A second band is
visible diagonally across this image -- the central band of our
Milky Way Galaxy.
If you wake up early, you will find that these same planets
remain visible in the morning sky this month, too.
APOD: 2020 April 21 - Eye on the Milky Way
Explanation:
Have you ever had
stars in your eyes?
It appears that the eye on the left does, and moreover it appears to be gazing at even more stars.
The
featured 27-frame mosaic was taken last July from
Ojas de Salar in the
Atacama Desert of
Chile.
The eye is actually a small
lagoon captured reflecting the
dark night sky as the Milky Way Galaxy arched overhead.
The seemingly smooth band of the
Milky Way is really composed of billions of stars, but decorated with filaments of light-absorbing dust and
red-glowing nebulas.
Additionally, both
Jupiter
(slightly left the galactic arch) and
Saturn
(slightly to the right) are visible.
The lights of small towns dot the unusual vertical horizon.
The rocky terrain around the
lagoon appears to some more like the surface of
Mars than our
Earth.
APOD: 2020 March 9 - Milky Way and Zodiacal Light over Chile
Explanation:
What is the band of light connecting the ground to the Milky Way?
Zodiacal light --
a stream of dust that orbits the
Sun in the inner
Solar System.
It is most easily seen just before sunrise, where it has been called a
false dawn, or just after sunset.
The origin of zodiacal dust remains a
topic of research, but is hypothesized to result from
asteroid collisions and
comet
tails.
The featured wide-angle image shows the central band of our
Milky Way Galaxy
arching across the top, while the
Large Magellanic Cloud (LMC), a
satellite galaxy to our Milky Way, is visible on the far left.
The image is a combination of
over 30 exposures taken last July near
La Serena
among the mountains of
Chile.
During the next two months,
zodiacal light can appear quite prominent in northern skies just after sunset.
APOD: 2020 January 29 - Milky Way over Yellowstone
Explanation:
The Milky Way was not created by an evaporating lake.
The pool
of vivid blue water, about 10 meters across, is known as
Silex Spring and is located in
Yellowstone National Park in
Wyoming,
USA.
Steam rises off
the spring, heated by a
magma chamber deep underneath known as the
Yellowstone hotspot.
The steam blurs the image of
Jupiter, making it seem unusually large.
Unrelated and far in the distance, the
central band of our
Milky Way Galaxy rises high overhead, a band lit by billions of stars.
The featured picture is a 3-image panorama taken last August.
If the Yellowstone hotspot causes another
supervolcanic eruption as it did
640,000 years ago, a
large part of North America would be affected.
APOD: 2019 November 19 - Milky Way over Uruguayan Lighthouse
Explanation:
Can a lighthouse illuminate a galaxy?
No, but in the featured image, gaps in light emanating from the
Jose Ignacio Lighthouse in
Uruguay
appear to match up nicely, although only momentarily and coincidently, with
dark dust lanes of our
Milky Way Galaxy.
The bright dot on the right is the planet
Jupiter.
The central band of the
Milky Way Galaxy is actually the central
spiral disk seen from within the disk.
The Milky Way band is
not easily visible
through city lights but can be quite spectacular to see in
dark skies.
The featured picture is actually the addition of ten consecutive images taken by the same camera from the same location.
The images were well planned to exclude direct light from the
famous
lighthouse.
APOD: 2019 October 10 - Mid-Air Meteor and Milky Way
Explanation:
On September 24, a late evening commercial flight from
Singapore to Australia offered stratospheric views of the
southern hemisphere's night sky, if you
chose a window seat.
In fact, a well-planned seating choice with a window facing
toward the Milky Way allowed the set up of a sensitive digital camera
on a tripod mount to record the
galaxy's central bulge
in a series of 10 second long exposures.
By chance, one of
the exposures
caught this
bright fireball meteor in the starry frame.
Reflected along the wing of the A380 aircraft, the brilliant greenish
streak is also internally reflected in the double layer window,
producing a fainter parallel to the original meteor track.
In the southern sky Jupiter is the bright source beneath
the galactic bulge and seen next to a green beacon,
just off the wing tip.
APOD: 2019 August 7 - Jupiter Engulfed and the Milky Way
Explanation:
This is a good month to see Jupiter.
To find
our Solar System's largest planet in your sky,
look toward the southeast just after sunset --
Jupiter should be the brightest object in that part of the sky.
If you have a binoculars or a small telescope, you should be able to
see Jupiter's
four brightest
moons right nearby,
and possibly some cloud bands.
The featured image was taken about a month ago from the
Persian Gulf.
The image shows Jupiter just to the right of the nearly vertical band of the central disk of our
Milky Way Galaxy.
The unnamed rock formations appear in projection like the jaws of a giant monster ready to engulf the Jovian giant.
When you
see Jupiter,
it may be interesting to know that NASA's robotic
Juno
spacecraft is simultaneously
visiting and studying the
giant planet.
Saturn is also visible this month, and although it is
nearby to Jupiter, it is not as bright.
APOD: 2019 June 17 - Milky Way over Pyramid of the Feathered Serpent
Explanation:
To see the feathered serpent
descend
the Mayan pyramid requires exquisite timing.
You must visit
El Castillo -- in
Mexico's
Yucatán Peninsula -- near an
equinox.
Then, during the late afternoon if the sky is clear,
the pyramid's own
shadows create triangles
that merge into the famous illusion of the
slithering viper.
Also known as the
Temple of Kukulkan, the impressive step-pyramid stands 30 meters tall and 55 meters wide at the base.
Built up as a series of square terraces by the
pre-Columbian civilization between the 9th and 12th century,
the structure can be used as a calendar and is noted for
astronomical alignments.
To see the central band of our
Milky Way Galaxy descend overhead the
Mayan pyramid,
however, requires less exquisite timing.
Even the
ancient Mayans
might have been impressed, though, to know that the exact positions of the Milky Way, Saturn (left) and Jupiter (right) in the featured image give it a time stamp more specific than
equinox -- in fact 2019 April 7 at 5 am.
APOD: 2019 May 27 - A Volcano of Fire under a Milky Way of Stars
Explanation:
Sometimes it's hard to decide which is more impressive -- the land or the sky.
On the land of the
featured image, for example, the Volcano of Fire
(Volcán de Fuego) is seen erupting topped by red-hot,
wind-blown ash
and with streams of glowing lava running down its side.
Lights from neighboring towns are seen through a thin haze below.
In the sky, though, the central plane of our
Milky Way Galaxy
runs diagonally from the upper left, with a fleeting
meteor just below, and the
trail of a satellite to the upper right.
The planet
Jupiter also appears toward the upper left,
with the bright star
Antares just to its right.
Much of the land and the sky were
captured together in a single, well-timed,
25-second exposure taken in mid-April from the side of
Fuego's sister
volcano Acatenango in
Guatemala.
The image of the meteor, though, was captured in a similar frame
taken about 30 minutes earlier -- when the volanic eruption was not as photogenic -- and added later digitally.
APOD: 2019 May 11 - Milky Way, Launch, and Landing
Explanation:
The Milky Way doesn't look quite this colorful and bright to the eye,
but a rocket launch does.
So a separate deep exposure with a sensitive digital camera was used in
this composite skyscape to bring out our galaxy's central crowded
starfields and cosmic dust clouds.
In the scene from Merritt Island National Wildlife Refuge, a nine
minute long exposure begun about 20 minutes after the
Miky Way image recorded a rocket
launch and
landing.
The Falcon 9 rocket, named for the Millennium Falcon of Star Wars fame,
appropriately launched a
Dragon
resupply ship to the International Space Station
in the early morning hours of May the 4th.
The plume and flare at the peak of the launch arc mark the rocket's
first stage boost back burn.
Two shorter diagonal streaks are the rocket engines bringing the Falcon 9 stage
back to an offshore landing on autonomous drone ship
Of course I Still Love You.
APOD: 2019 April 19 - Milky Way in Northern Spring
Explanation:
A
postcard from planet Earth, this springtime night skyscape
looks over Alandan lake in the Alborz mountains.
Taken
after local midnight
on April 17, the central Milky Way
is rising over the region's southeast horizon.
Its luminous track of stars and nebulae
along the plane of our galaxy are reflected in
the mirror-like lake.
The brightest celestial beacon mingled with the diffuse galactic
starlight is Jupiter.
Slightly dimmer, Saturn is below and left just above the mountains.
As spring brought leaves to the trees and
the galactic center to the northern night
the photographer found it also
gave frogs their voices,
heard like a melody across the calm water.
APOD: 2019 January 14 - Meteor and Milky Way over the Alps
Explanation:
Now this was a view with a thrill.
From
Mount Tschirgant
in the
Alps,
you can see not only nearby towns and distant
Tyrolean peaks,
but also, weather permitting, stars, nebulas, and the band of the
Milky Way Galaxy.
What made the arduous climb worthwhile this night,
though, was another peak -- the peak of the 2018
Perseids
Meteor
Shower.
As hoped, dispersing clouds allowed a picturesque sky-gazing session that included many faint meteors, all while a carefully positioned camera took a series of exposures.
Suddenly, a thrilling meteor --
bright and
colorful -- slashed down right next the nearly
vertical band of the Milky Way.
As luck would have it, the camera caught it too.
Therefore, a new image in the series was quickly taken with one of the
sky-gazers posing on the nearby peak.
Later, all of the images were digitally combined.
APOD: 2019 January 12 - Milky Way Falls
Explanation:
It can be the driest place on planet Earth, but
water still flows in Chile's Atacama desert, high in the mountains.
After discovering this small creek with running water, the photographer
returned to the site to watch the Milky Way rise in the dark
southern skies, calculating the moment when Milky Way and
precious flowing water would meet.
In the panoramic night skyscape,
stars and nebulae immersed
in the glow along the Milky Way itself also shared that moment
with the Milky Way's
satellite galaxies
the Large and Small
Magellanic clouds above the horizon
at the right.
Bright star Beta Centauri is poised at the very top of the waterfall.
Above it lies the dark expanse of the
Coalsack
nebula and the stars of the Southern Cross.
APOD: 2018 October 19 - Summer to Winter Milky Way
Explanation:
Taken near local midnight, this autumn night's panorama follows the
arch of the Milky Way across the northern horizon from the
High Fens, Eifel Nature Park at the border of Belgium and Germany.
Shift your gaze across
the wetlands from west to east (left to right) and you
can watch stars once more prominent in northern summer give way to
those that will soon dominate northern winter nights.
Setting, wanderer Mars is brightest at the far left,
still shining against
almost overwhelming
city lights along the southwestern horizon.
Bright stars Altair, Deneb, and Vega form the northern sky's
summer triangle,
straddling the Milky Way left of center.
Part of the
winter hexagon Capella and Aldebaran,
along with the beautiful Pleiades star cluster
shine across the northeastern sky.
The line-of-sight along the hikers boardwalk leads almost directly
toward the Big Dipper, an
all season asterism from these northern
latitudes.
Follow the Big Dipper's pointer stars to
Polaris and the north celestial pole nearly centered above it.
Andromeda, the other large galaxy
in the skyscape, is near the top of the frame.
APOD: 2018 September 15 - Mont Blanc, Meteor, and Milky Way
Explanation:
Snowy
Mont Blanc
is near the center of this atmospheric night skyscape.
But high, thin clouds fogged the skies at the photographer's location,
looking south toward Europe's highest peak from the southern Swiss Alps.
Still, the 13 second exposure finds the faint star fields and dark rifts of
the Milky Way above the
famous
white mountain.
Bloated by the mist, bright planet Saturn and Antares (right),
alpha star of Scorpius, shine through the clouds to flank the
galaxy's central bulge.
The high-altitude
scene is from the rewarding night of August 12/13, so it also
includes the green trail of a Perseid
meteor shooting along the galactic plane.
APOD: 2018 September 11 - Milky Way over Trolls Tongue
Explanation:
You have to take a
long hike to see the Troll's Tongue -- ten hours over rocky terrain.
And in this case, it took three trips to capture the
landform below a clear night sky.
Trolltunga itself is a
picturesque rock protrusion
extending about 700 meters over mountainous cliffs near
Lake Ringedalsvatnet in
Norway.
The overhang is made of billion-year-old
Precambrian
bedrock that was carved out by glaciers during an ice-age about 10,000 years ago.
The featured picture is a composite of two exposures, a 15-second image of the
foreground
Earth
followed 40 minutes later by an 87-second exposure of the
background sky.
Thousands of discernable stars dot the backdrop
starscape
in addition to billions of
unresolved stars in the nearly vertical
band of our Milky Way Galaxy.
APOD: 2018 August 11 - Moon, Mars, and Milky Way
Explanation:
Just two weeks ago,
dark skies over the desert in northern Iran
held this alluring celestial vista.
The dramatic digital mosaic finds the Moon and Mars
alongside the Milky Way's dusty rifts, stars, and nebulae.
Captured through a series of exposures to cover a range in brightness,
that night's otherwise Full Moon is immersed in Earth's shadow.
It actually appears fainter
and redder than the Red Planet itself
during the widely watched total lunar eclipse.
For cosmic tourists,
the skyscape also includes the
Lagoon (M8) and Trifid (M20)
nebulae and planet Saturn shining against the Milky Way's
pale starlight.
The Moon isn't quite done with
its
shadow play, though.
Today, the New Moon
partially eclipses the Sun for much of northern planet Earth.
APOD: 2018 July 20 - The Teapot and the Milky Way
Explanation:
The recognizable stars
of the Teapot asterism in the constellation
Sagittarius posed with the Milky Way over Death Valley, planet Earth
on this quiet, dark night.
The surreal scene was appropriately captured from
Teakettle Junction,
marked by the wooden sign adorned with
terrestrial teapots and kettles on the rugged road to
Racetrack Playa.
Shining against the luminous starlight of the central Milky Way
is bright planet
Saturn,
just above the star at the
celestial teapot's peak.
But the brightest celestial beacon, high above the southern horizon, is
an orange tinted
Mars at upper left
in the frame.
APOD: 2018 June 9 - Countryside Mars and Milky Way
Explanation:
Mars shines brightly
now in planet Earth's sky.
Seen with a yellowish hue it rises over the hills and far away in
this serene night skyscape, a countryside panorama recorded
last month from Parque Nacional de Cabaneros in Spain.
The Milky Way too
extends above the distant hills into a starry sky.
Its faint pinkish nebulae, cosmic rifts and rivers of dust
are mingled with the pale, diffuse glow of starlight.
Mimicking
Mars' yellow tint, bright star Antares shines to the
right of the central Milky Way starclouds.
Of course,
CubeSats from Earth
are on their way to the Red Planet.
APOD: 2018 May 17 - Milky Way vs Airglow Australis
Explanation:
Captured last week
after sunset on a Chilean autumn night,
an exceptional airglow floods this allsky view
from Las Campanas Observatory.
The airglow was so intense it diminished parts of the Milky Way
as it arced horizon to horizon above the high Atacama desert.
Originating at an altitude similar to aurorae, the luminous airglow is
due
to chemiluminescence, the
production of light through chemical excitation.
Commonly recorded in color by sensitive
digital cameras, the airglow emission here is fiery in appearance.
It is predominately
from atmospheric
oxygen atoms at extremely low densities and has often been present
during southern hemisphere nights over the last few years.
Like the Milky Way,
on that dark night the strong airglow was very visible
to the eye, but seen without color.
Jupiter is the brightest celestial beacon though,
standing opposite the Sun and near the central bulge of the Milky Way
rising above the eastern (top) horizon.
The Large and Small
Magellanic clouds both shine through the airglow
to the lower left of the galactic plane, toward the southern horizon.
APOD: 2018 April 27 - Gaia's Milky Way
Explanation:
This grand allsky view
of our Milky Way and nearby galaxies is
not a photograph.
It's a map based on individual measurements for
nearly 1.7 billion stars.
The astronomically rich data set used to create it, the
sky-scanning
Gaia satellite's
second data release,
includes remarkably precise determinations of position, brightness, colour, and
parallax distance for 1.3 billion stars.
Of course, that's about 1 percent of the total number of stars in
the Milky Way.
The flat plane of our galaxy still dominates the view.
Home to most
Milky Way stars it stretches across the center
of Gaia's stellar data map.
Voids and rifts along the galactic plane correspond to
starlight-obscuring interstellar dust clouds.
At lower right are stars of the Large and Small Magellanic Clouds,
neighboring galaxies that lie
just
beyond the Milky Way.
APOD: 2018 April 18 - Milky Way over Deadvlei in Namibia
Explanation:
What planet is this?
It is the only planet currently known to have trees.
The trees in
Deadvlei,
though, have been dead for over 500 years.
Located in
Namib-Naukluft Park in
Namibia
(Earth), saplings grew after rainfall caused a
local river to overflow,
but died after
sand dunes shifted to section off the river.
High above and far in the distance, the band of our
Milky Way Galaxy forms an arch over a large stalk in this well-timed composite image, taken last month.
The soil of white
clay appears to glow by reflected starlight.
Rising on the left, under the Milky Way's arch, is a band of
zodiacal light -- sunlight reflected by dust orbiting in the inner Solar System.
On the right, just above one of
Earth's
larger sand dunes, an
astute eye can find the
Large Magellanic Cloud,
a satellite galaxy of our galaxy.
Finding the
Small Magellanic Cloud in the
featured image, though, is perhaps too hard.
APOD: 2018 April 3 - The Milky Way over the Seven Strong Men Rock Formations
Explanation:
You may have heard of the
Seven Sisters in the sky,
but have you heard about the Seven Strong Men on the ground?
Located just west of the
Ural Mountains, the unusual
Manpupuner rock formations are one of the
Seven Wonders of Russia.
How these ancient 40-meter high
pillars formed is yet unknown.
The persistent photographer of
this featured image battled
rough terrain and uncooperative weather to capture these
rugged stone towers in winter at night, being finally successful in February of 2014.
Utilizing the camera's time delay feature,
the photographer holds a flashlight in the foreground near one of the snow-covered
pillars.
High above, millions of stars shine down, while the band of our
Milky Way Galaxy crosses diagonally down from the upper left.
APOD: 2018 March 6 - Colorful Airglow Bands Surround Milky Way
Explanation:
Why would the sky glow like a giant repeating rainbow?
Airglow.
Now air glows all of the time, but it is usually hard to see.
A disturbance however -- like an approaching storm --
may cause noticeable rippling in the
Earth's atmosphere.
These gravity waves are
oscillations in air analogous to those created when a
rock is thrown in calm water.
Red airglow likely originates from
OH molecules
about 87-kilometers high, excited by
ultraviolet light from the Sun, while orange and green
airglow
is likely caused by
sodium and
oxygen atoms slightly higher up.
While driving near
Keluke Lake in
Qinghai Provence in
China,
the photographer originally noticed mainly the impressive central band of the
Milky Way Galaxy.
Stopping to photograph it, surprisingly, the resulting sensitive camera image showed
airglow bands to be quite prominent and span the entire sky.
The featured image has been digitally enhanced to make the colors more vibrant.
APOD: 2017 December 21 - Solstice Sun and Milky Way
Explanation:
Welcome to
December's solstice, first day of winter in the north and
summer for the southern hemisphere.
Astronomical markers of the seasons,
solstice
and equinox dates are based
on the Sun's place in its annual journey along the ecliptic,
through planet Earth's sky.
At this solstice, the Sun reaches its maximum southern
declination of -23.5 degrees today at 16:28 UTC, while
its right ascension coordinate on the
celestial sphere
is 18 hours.
That puts the Sun in the constellation Sagittarius in a direction near
the center of our Milky Way galaxy.
In fact, if you could see today's Solstice Sun against faint background
stars and nebulae (that's really hard to do, especially in the daytime ...)
your view might look something like this composited panorama.
To make it, images of
our fair galaxy
were taken under dark Namibian night skies, then stitched together
in a panoramic view.
From a snapshot made on December 21, 2015, the Sun was digitally
overlayed as a brilliant star at today's northern winter
solstice position, close to the center of
the Milky Way.
APOD: 2017 October 10 - Milky Way and Zodiacal Light over Australian Pinnacles
Explanation:
What strange world is this?
Earth.
In the foreground of the featured image are the
Pinnacles,
unusual rock spires in
Nambung National Park in Western
Australia.
Made of ancient sea shells
(limestone), how these human-sized
picturesque spires formed remains a
topic of research.
The panorama was taken last month.
A ray of
zodiacal light,
sunlight reflected by dust grains orbiting between the planets in the
Solar System,
rises from the horizon near the image center.
Arching across the top is the central band of our
Milky Way Galaxy.
The planets
Jupiter and
Saturn, as well as several famous
stars are also visible in the background night sky.
APOD: 2017 August 21 - Milky Way over Chilean Volcanoes
Explanation:
Sometimes, the sky mimics the ground.
Taken in 2017 May from the
Atacama Desert in
Chile,
the foreground of the
featured image
encompasses the dipping edge of the
caldera of an extinct volcano.
Poetically
echoing the dip below is the arch of our
Milky Way Galaxy above.
Many famous icons dot this southern nighttime vista, including the
center of our Milky Way Galaxy on the far left,
the bright orange star Antares also on the left,
the constellation of the Southern
Cross
near the top of the arch, and the red-glowing
Gum Nebula on the far right.
Just above the horizon and splitting
two distant volcanic peaks
near the image center is the
Large Magellanic Cloud -- the largest
satellite galaxy of the Milky Way.
APOD: 2017 August 6 - Milky Way and Exploding Meteor
Explanation:
Next weekend the
Perseid Meteor Shower reaches its maximum.
Grains of icy rock will
streak across the sky
as they evaporate during entry into
Earth's atmosphere.
These grains were shed from
Comet Swift-Tuttle.
The Perseids result from the annual crossing of the Earth through
Comet Swift-Tuttle's orbit, and are
typically the most active
meteor shower of the year.
Although it is hard to predict the level of activity in
any meteor shower, in a clear dark sky an observer might see a
meteor a minute.
This year's
Perseids
peak nearly a week after
full Moon,
and so some faint meteors will be lost to the lunar skyglow.
Meteor showers in general are best be seen from a relaxing position, away from lights.
Featured here
is a meteor caught
exploding during the 2015 Perseids above
Austria
next to the central band of our
Milky Way Galaxy.
APOD: 2017 July 26 - The Milky Way over Monument Valley
Explanation:
You don't have to be at Monument Valley to see the Milky Way arc
across the sky like this -- but it helps.
Only at Monument
Valley
USA would you see a
picturesque
foreground that includes these iconic rock peaks called
buttes.
Buttes are composed of hard rock left behind after water
has eroded away the surrounding soft rock.
In the
featured
image taken a month ago, the closest
butte on the left and
the butte to its right are known as
the Mittens, while
Merrick Butte
can be seen farther to the right.
Green airglow fans up from the horizon.
High overhead stretches
a band of diffuse light that is the central disk of our
spiral
Milky Way Galaxy.
The band of the Milky Way can be
spotted by almost
anyone on almost any clear night when
far enough from a city and
surrounding bright lights,
but a sensitive digital camera is needed to capture these colors
in a dark night sky.
APOD: 2017 June 10 - Saturn in the Milky Way
Explanation:
Saturn
is near opposition in planet Earth's sky.
Rising at sunset and shining brightly throughout the night,
it also lies near a line-of-sight to crowded starfields, nebulae,
and obscuring dust clouds
along the Milky Way.
Whitish Saturn is up and left of center in this gorgeous
central Milky Way skyscape, a two panel mosaic recorded
earlier this month.
You can find
the bright planet above the bowl of the dusty
Pipe nebula,
and just beyond the end of a
dark river to Antares,
alpha star of the constellation Scorpius.
For now the best views
of the ringed giant planet are from
the Saturn-orbiting Cassini spacecraft, though.
Diving close,
Cassini's Grand Finale orbit number 8
is in progress.
APOD: 2017 March 28 - King of Wings Hoodoo under the Milky Way
Explanation:
This rock structure is not only surreal -- it's real.
The reason it's not more famous is that it is, perhaps, smaller than one might guess: the capstone rock overhangs only a
few meters.
Even so, the
King of Wings outcrop, located in
New Mexico,
USA, is a fascinating example of an unusual type of rock structure called a
hoodoo.
Hoodoos may
form when a layer of hard rock overlays a layer of
eroding
softer rock.
Figuring out the details of incorporating
this hoodoo into a night-sky photoshoot took over a year.
Besides
waiting for a suitably picturesque night behind a sky with few clouds,
the foreground had to be
artificially lit
just right relative to the natural glow of the background.
After much planning and waiting, the final shot,
featured here,
was taken in May 2016.
Mimicking the horizontal bar, the background sky features the band of our
Milky Way Galaxy stretching overhead.
APOD: 2017 February 3 - Milky Way with Airglow Australis
Explanation:
Captured last April
after sunset on a Chilean autumn night
an exceptionally intense airglow flooded this scene.
The panoramic skyscape is also filled with
stars, clusters, and nebulae along the southern Milky Way
including the Large and Small Magellanic clouds.
Originating at an altitude similar to aurorae,
the luminous airglow is
due
to chemiluminescence, the
production of light through chemical excitation.
Commonly recorded with a greenish tinge by sensitive
digital cameras, both red and green airglow emission here
is predominately
from atmospheric
oxygen atoms at extremely low densities and has often been present in
southern hemisphere nights during the last few years.
Like the Milky Way
on that dark night the strong airglow was visible
to the eye, but seen without color.
Mars, Saturn, and bright star Antares in Scorpius
form the celestial triangle anchoring the scene on the left.
The road leads toward the 2,600 meter high mountain Cerro Paranal and
the European Southern Observatory's
Very Large
Telescopes.
APOD: 2016 November 30 - Milky Way over Shipwreck
Explanation:
What happened to this ship?
It was carried aground by a giant storm that struck the coast of
Argentina in 2002.
The pictured abandoned boat, dubbed
Naufragio del Chubasco,
wrecked near the nearly abandoned town of
Cabo Raso (population: 1).
The rusting ship
provides a picturesque but perhaps creepy foreground for the beautiful sky above.
This sky is crowned by the grand arch of our
Milky Way and features galaxies including the
Large and
Small Magellanic Clouds, stars including
Canopus and
Altair, planets including
Mars and
Neptune,
and nebulas including the
Lagoon,
Carina, and the
Coal Sack.
The mosaic was composed from over 80 images taken in early September.
A 360-degree interactive panoramic version of this image is also available.
The adventurous astrophotographer reports that the creepiest part of taking this picture was not the abandoned ship, but the unusual prevalence of black and hairy
caterpillars.
APOD: 2016 November 10 - Great Rift Near the Center of the Milky Way
Explanation:
Over 100 telescopic image
panels in this stunning vertical mosaic span
about 50 degrees
across
the night sky.
They follow part of the
Great Rift, the
dark river
of dust and molecular gas that stretches
along the plane of our Milky Way Galaxy.
Start at top center and you can follow the
galactic
equator down through brighter stars in constellations Aquila,
Serpens Cauda, and Scutum.
At the bottom is Sagittarius near the center of the Milky Way.
Along the way you'll encounter many obscuring
dark
nebulae hundreds of light-years distant flanked by bands of
Milky Way starlight, and the telltale reddish glow of starforming regions.
Notable Messier objects
include The Eagle (M16) and Omega (M17)
nebulae, the Sagittarius Star Cloud (M24), the beautiful Trifid (M20)
and the deep Lagoon (M8).
APOD: 2016 August 26 - The Milky Way Sets
Explanation:
Under dark skies the
setting of the Milky Way can be a dramatic sight.
Stretching nearly parallel to the horizon, this rich,
edge-on vista
of our galaxy above the dusty Namibian desert stretches from
bright, southern Centaurus (left) to
Cepheus in the north (right).
From early August, the digitally stitched, panoramic night skyscape
captures the Milky Way's congeries of stars and rivers of cosmic dust,
along with colors of nebulae not readily seen with the eye.
Mars, Saturn, and Antares, visible even in more luminous night
skies, form the the bright celestial
triangle just touching the trees
below the galaxy's central bulge.
Of course, our own galaxy is not the only galaxy in the scene.
Two other major members of our local group,
the Andromeda Galaxy and the Triangulum Galaxy,
lie near the right edge of the frame, beyond the
arc of the setting Milky Way.
APOD: 2016 July 23 - Summer Planets and Milky Way
Explanation:
Lights sprawl
toward the horizon in this night skyscape from
Uludag National Park, Bursa Province, Turkey,
planet Earth.
The stars and nebulae of the Milky Way are still visible though,
stretching above the lights on the northern summer night while
three other planets
shine brightly.
Jupiter is at the far right, Mars near the center of the frame,
and Saturn is just right of the bulging center of our galaxy.
Because the panoramic scene was captured on July 6, all three planets
pictured were hosting orbiting, operational, robotic
spacecraft
from Earth.
Popular
Mars has five (from three different space agencies):
MAVEN (NASA),
Mars Orbiter Mission (India),
Mars Express (ESA),
Mars Odyssey (NASA),
Mars Reconnaissance Orbiter (NASA).
Ringed Saturn hosts the
daring Cassini spacecraft.
Just arrived, Juno now orbits ruling
gas giant Jupiter.
APOD: 2016 July 2 - Firefly Trails and the Summer Milky Way
Explanation:
A camera fixed low to a tripod on a
northern summer's eve
captured the series of images used in this serene, southern Ontario skyscape.
The lakeside view frames our fair galaxy above calm water
and the night's quintessential luminous apparitions.
But the trails of light are neither
satellite glint, nor
meteor flash, nor
auroral glow.
In the wide-field composite constructed with four consecutive 15
second exposures, a pulsing
firefly
enters at the right, first wandering toward the camera,
then left and back toward the lake,
the central Milky Way rising in the background.
APOD: 2016 May 24 - Milky Way Over the Spanish Peaks
Explanation:
That's not lightning, and it did not strike between those mountains.
The diagonal band is actually the central band of our Milky Way Galaxy, while the twin peaks are actually called the
Spanish Peaks -- but located in
Colorado,
USA.
Although each
Spanish peak
is composed of a slightly different type of rock, both are approximately
25 million years old.
This serene yet spirited image composite was
meticulously created by merging a series of images all taken from the same location on one night and early last month.
In the first series of exposures, the background sky was built up, with great detail being revealed in the
Milky Way dust lanes as well as the
large colorful region
surrounding the star
Rho Ophiuchus just right of center.
One sky image, though, was taken using a
fogging filter
so that brighter stars would appear more spread out and so more prominent.
As a bonus, the planets
Mars and
Saturn
are placed right above peaks and make an orange triangle with the bright star
Antares.
Later that night, after the moonrise, the Moon itself
naturally illuminated the snow covered mountain tops.
APOD: 2016 May 21 - Milky Way and Planets Near Opposition
Explanation:
In this early May night skyscape,
a mountain road near Bursa, Turkey
seems to lead toward bright planets Mars and Saturn
and the center of our Milky Way Galaxy, a direction
nearly opposite the Sun in planet Earth's sky.
The brightest celestial beacon on the scene,
Mars,
reaches its opposition tonight and Saturn in early June.
Both will remain
nearly opposite the Sun,
up all night and close
to Earth for the coming weeks, so the time is right for
good
telescopic viewing.
Mars and Saturn form the tight
celestial triangle with
red giant star Antares just right of the Milky Way's central bulge.
But tonight the Moon
is also at opposition.
Easy to see near bright Mars and Saturn,
the Full Moon's light will wash out the central Milky Way's
fainter starlight though, even in dark mountain skies.
APOD: 2016 May 15 - Milky Way Over Quiver Tree Forest
Explanation:
In front of a famous background of stars and galaxies lies some of Earth's more unusual trees.
Known as quiver trees, they are actually
succulent
aloe plants that can grow to tree-like proportions.
The quiver tree
name is derived from the historical usefulness of their hollowed branches as dart holders.
Occurring primarily in southern
Africa, the trees pictured in the
above 16-exposure composite are in
Quiver Tree Forest
located in southern Namibia.
Some of the tallest quiver trees
in the park are estimated to be about 300 years old.
Behind
the trees
is light from the small town of
Keetmanshoop,
Namibia.
Far in the distance,
arching across the background, is the majestic
central band of our
Milky Way Galaxy.
Even further in the distance, visible on the image left, are the
Large and
Small Magellanic Clouds,
smaller satellite galaxies of the
Milky Way that are
prominent in the skies of
Earth's southern hemisphere.
APOD: 2016 May 14 - Falcon 9 and Milky Way
Explanation:
On May 6, the after midnight launch of a
SpaceX Falcon 9 rocket
lit up dark skies over Merritt Island, planet Earth.
Its second stage
bound for Earth orbit,
the rocket's arc seems to be on course for the center of the Milky Way in
this pleasing composite image
looking toward the southeast.
Two consecutive exposures made with camera fixed to a tripod
were combined to follow rocket and home galaxy.
A 3 minute long exposure at low sensitivity
allowed the rocket's first stage burn to trace the bright orange
arc and a 30 second exposure at high sensitivity captured the stars and the
faint Milky Way.
Bright orange Mars dominates
the starry sky at the upper right.
A few minutes later, booster engines were restarted and the
Falcon 9's first stage
headed for a
landing on the autonomous spaceport drone ship
Of Course I Still Love You,
patiently waiting in the Atlantic 400 miles east of
the Cape Canaveral launch site.
APOD: 2016 April 23 - Milky Way in Moonlight
Explanation:
A waning crescent moon, early morning twilight, and
Al Hamra's city lights
on the horizon can't hide the central Milky Way in this skyscape from
planet Earth.
Captured in a single exposure,
the dreamlike
scene looks southward
across the region's grand canyon from Jabal Shams (Sun Mountain),
near the highest peak in Oman, on the
Arabian Peninsula.
Mist, moonlight, and shadows still play along the steep canyon walls.
Dark rifts
along the luminous band of the Milky Way are the galaxy's
cosmic dust clouds.
Typically hundreds of light-years distant, they obscure starlight along the
galactic plane, viewed edge-on from the
Solar System's
perspective.
APOD: 2016 March 25 - Close Comet and the Milky Way
Explanation:
Comet 252P/Linear's
lovely greenish coma is easy to spot in this expansive southern skyscape.
Visible to the naked eye from the
dark site near
Flinders, Victoria, Australia, the comet appears tailless.
Still, its surprisingly bright coma spans about 1 degree, posed
here below the nebulae, stars, and dark rifts of the Milky Way.
The five panels used in the wide-field mosaic were captured after moonset
and before morning twilight on March 21.
That was less than 24 hours from the comet's closest
approach, a mere 5.3 million kilometers
from our fair planet.
Sweeping quickly across the sky because it is so close to Earth,
the comet should be spotted in the coming days by
northern hemisphere
comet watchers.
In predawn but moonlit skies it will move through
Sagittarius and Scorpius seen toward the southern horizon.
That's near the triangle formed by bright, yellowish, Mars, Saturn, and
Antares at the upper left
of this frame.
APOD: 2016 February 17 - Milky Way over the Pinnacles in Australia
Explanation:
What strange world is this?
Earth.
In the foreground of the featured image are the
Pinnacles,
unusual rock spires in
Nambung National Park in Western
Australia.
Made of ancient sea shells
(limestone), how these human-sized
picturesque spires formed remains unknown.
In the background, just past the end of the central Pinnacle, is a bright crescent Moon.
The eerie glow around the Moon is mostly
zodiacal light,
sunlight reflected by dust grains orbiting between the planets in the
Solar System.
Arching across the top is the central band of our
Milky Way Galaxy.
Many famous
stars and
nebula are also visible in the background night sky.
The featured 29-panel panorama was taken and composed
last September after detailed planning that involved the Moon, the rock spires, and their corresponding
shadows.
Even so, the strong zodiacal light was a pleasant
surprise.
APOD: 2015 November 7 - Earth and Milky Way from Space
Explanation:
Since
November 2000, people have been living
continuously on the International Space Station.
To celebrate humanity's 15th anniversary
off planet Earth,
consider this
snapshot
from space of our galaxy and
our home world posing together beyond the orbital outpost.
The Milky Way stretches below the curve of Earth's limb in the scene
that also records a faint red, extended airglow.
The galaxy's central bulge appears with starfields
cut by dark rifts of obscuring interstellar dust.
The picture was taken by Astronaut Scott Kelly on August 9, 2015,
the 135th day of his
one-year mission in space.
APOD: 2015 November 1 - The Milky Way Over Monument Valley
Explanation:
You don't have to be at Monument Valley to see the Milky Way arch across the sky like this -- but it helps.
Only at Monument Valley
USA
would you see a
picturesque foreground
that includes these iconic rock peaks called
buttes.
Buttes are composed of hard rock left behind after water
has eroded away the surrounding soft rock.
In the featured image taken in 2012, the closest butte on the left and
the butte to its right are known as
the Mittens, while
Merrick Butte
can be seen just further to the right.
High overhead stretches a band of diffuse light that is the central disk of our
spiral
Milky Way Galaxy.
The band of the Milky Way can be
spotted by almost anyone on
almost any clear night when
far enough from a city and
surrounding bright lights.
APOD: 2015 September 22 - Milky Way over Bosque Alegre Station in Argentina
Explanation:
What are those streaks of light in the sky?
First and foremost, the arching structure is the central band of our
Milky Way galaxy.
Visible in
this galactic band
are millions of distant stars mixed with numerous lanes of dark dust.
Harder to discern is a nearly vertical beam of light rising from the horizon, just to the right of the image center.
This beam is zodiacal light,
sunlight scattered by dust in our Solar System that may be
surprisingly prominent just after sunset or just before sunrise.
In the foreground are several telescopes of the
Bosque Alegre Astrophysical Station
of the National University of Cordoba in
Argentina.
The station schedules
weekend tours and conducts research into the nature of
many astronomical objects including
comets,
active galaxies, and
clusters of galaxies.
The featured image was taken early this month.
APOD: 2015 September 4 - Milky Way with Airglow Australis
Explanation:
After sunset on September 1, an exceptionally
intense, reddish airglow flooded this Chilean winter night skyscape.
Above a sea of clouds and flanking the
celestial Milky Way, the airglow seems to ripple and flow
across the northern horizon in
atmospheric waves.
Originating at an altitude similar to aurorae,
the luminous airglow is instead
due
to chemiluminescence, the
production of light through chemical excitation.
Commonly captured with a greenish tinge by sensitive
digital cameras, this reddish airglow emission is
from OH molecules and oxygen atoms at extremely low densities
and has often been present in
southern hemisphere nights during the last few years.
On this night it was visible to the eye, but seen without color.
Antares and the central Milky Way
lie near the top, with bright star Arcturus at left.
Straddling the Milky Way close to the horizon are Vega, Deneb,
and Altair, known in northern nights as the
stars of the Summer Triangle.
APOD: 2015 August 25 - Meteors and Milky Way over Mount Rainier
Explanation:
Despite appearances, the sky is not falling.
Two weeks ago, however, tiny bits of comet dust were.
Featured here is the
Perseids meteor shower as captured over
Mt. Rainier,
Washington,
USA.
The image was created from a two-hour time lapse video, snaring over 20 meteors, including one that
brightened dramatically on the image left.
Although each
meteor train typically lasts less than a second,
the camera was able to capture their
color progressions as they disintegrated in the
Earth's atmosphere.
Here an initial green
tint may be indicative of
small amounts of glowing magnesium atoms that were knocked off the
meteor by atoms in the
Earth's atmosphere.
To cap things off, the central band of our
Milky Way Galaxy
was simultaneously photographed rising straight up behind the snow-covered peak of
Mt. Rainier.
Another
good meteor shower
is expected in mid-November when debris from a different comet intersects Earth as the
Leonids.
APOD: 2015 August 13 - Moonless Meteors and the Milky Way
Explanation:
Have you watched the
Perseid meteor shower?
Though the annual shower's predicted peak was last night,
meteor activity should continue tonight (August 13/14),
best enjoyed by just looking up in clear, dark skies
after midnight.
Of course,
this year's Perseid shower has the advantage
of being active near the August 14 New Moon.
Since the nearly New Moon doesn't rise before the
morning twilight many fainter meteors are easier to spot until then,
with no interference from bright moonlight.
The Perseid meteor shower last occurred near a New Moon
in 2013.
That's when the exposures used to construct
this image were made, under dark, moonless skies
from Hvar Island off the coast of Croatia.
The widefield
composite includes 67
meteors streaming from
the heroic constellation Perseus, the shower's radiant,
captured during 2013 August 8-14 against
a background of faint
zodiacal light and the Milky Way.
The next moonless Perseid meteor shower will be in August 2018.
APOD: 2015 July 30 - Milky Way over Uluru
Explanation:
The central regions of our Milky Way Galaxy rise above
Uluru/Ayers Rock in
this striking
night
skyscape.
Recorded on July 13, a faint airglow along the horizon shows
off central Australia's most
recognizable
landform in silhouette.
Of course the Milky Way's own cosmic dust clouds appear in
silhouette too, dark rifts along the galaxy's faint
congeries of stars.
Above the central bulge,
rivers of cosmic dust converge on a
bright yellowish supergiant star Antares.
Left of Antares, wandering
Saturn shines in the night.
APOD: 2015 July 27 - Milky Way and Aurora over Antarctica
Explanation:
It has been one of the better skies of this long night.
In
parts of
Antarctica, not only is it winter, but the Sun can spend weeks below the horizon.
At China's
Zhongshan Station,
people sometimes venture out into the cold to photograph a spectacular night sky.
The featured image from one such outing was taken in mid-July,
just before the end of this
polar night.
Pointing up, the
wide angle lens
captured not only the ground at the bottom, but at the top as well.
In the foreground is a colleague also taking pictures.
In the distance, a spherical satellite receiver and several
windmills
are visible.
Numerous stars dot the night sky, including
Sirius and
Canopus.
Far in the background, stretching overhead from horizon to horizon, is the
central band of our
Milky Way Galaxy.
Even further in the distance, visible as extended smudges near the top, are the
Large and
Small Magellanic
Clouds, satellite galaxies near our huge
Milky Way Galaxy.
APOD: 2015 July 7 - The Milky Way from a Malibu Sea Cave
Explanation:
What’s happening outside this cave?
Nothing unexpected – it’s just the central band of our
Milky Way Galaxy passing by.
As the Earth turns, the band of our Galaxy appears to
rotate and shift along the horizon.
The featured image was taken by a photographer who professes a passion for locating sea caves, and who found this spectacular grotto in
Leo Carrillo State Park near
Malibu,
California,
USA.
After
some planning, he timed
this single shot image
through the 10-meter high
cave entrance
to show the Milky Way far in the distance.
In the foreground, several rocks about one meter across are visible.
Visible in the background starscape are millions of stars including the relatively bright and orange
Antares,
situated just to the right of the image center.
APOD: 2015 June 8 - The Milky Way over the Temple of Poseidon
Explanation:
What's that glowing in the distance?
Although it may look like a
lighthouse, the rays of light near the horizon actually emanate from the
Temple of Poseidon at
Cape Sounion,
Greece.
Some temple
lights are even reflected in the
Aegean Sea in the foreground.
Although meant to be a monument to the sea, in this image,
the temple's lights seem to be pointing out locations on the sky.
For example, the wide ray toward the right fortuitously points toward the
Lagoon Nebula in the central band of our
Milky Way, which runs diagonally down the image from the upper left.
Also, the nearly vertical beam seems to point toward the star clouds near the direction of the
Wild Duck open cluster of stars.
The featured image was taken less than three weeks ago.
APOD: 2015 April 24 - Blue Tears and the Milky Way
Explanation:
Lapping at rocks
along the shore of the Island of Nangan, Taiwan,
planet Earth,
waves are infused with a subtle blue light in this
sea and night skyscape.
Composed of a series of long exposures made on April 16
the image captures the faint glow from
Noctiluca scintillans.
Also known as sea sparkles or blue tears,
the marine plankton's bioluminescence is stimulated by wave motion.
City lights along the coast of mainland China shine
beneath low clouds in the west but stars and the
faint Milky Way
still fill the night above.
Over the horizon the galaxy's central bulge and dark rifts
seem to echo the rocks
and luminous waves.
APOD: 2015 April 23 - Meteor in the Milky Way
Explanation:
Earth's April showers include the
Lyrid Meteor Shower,
observed for more than 2,000 years
when the planet makes its annual passage
through the
dust stream of long-period Comet Thatcher.
A grain of that comet's dust, moving 48 kilometers per second
at an altitude of 100 kilometers or so,
is swept up in this night sky view from
the early hours of April 21.
Flashing toward the southeastern horizon,
the meteor's brilliant streak
crosses the central region of the rising Milky Way.
Its trail points back
toward the shower's radiant
in the constellation Lyra,
high in the northern springtime sky and off the top of the frame.
The yellowish hue of giant star Antares shines to
the right of the Milky Way's bulge.
Higher still is bright planet Saturn, near the right edge.
Seen from Istra, Croatia, the Lyrid meteor's
greenish glow reflects in the waters of the Adriatic Sea.
APOD: 2015 April 13 - Milky Way over Erupting Volcano
Explanation:
The view was worth the trip.
Battling
high winds,
cold temperatures, and
low oxygen, the
trek to
near the top of the volcano
Santa Maria in
Guatemala -- while carrying sensitive camera equipment -- was lonely and difficult.
Once set up, though, the camera captured
this breathtaking vista during the early morning hours of February 28.
Visible on the ground are six volcanoes of the
Central America Volcanic Arc, including
Fuego, the
Volcano of Fire, which is
seen erupting in the distance.
Visible in the sky, in separate exposures taken a few minutes later,
are many stars much further in the distance, as well as the
central band of our
Milky Way Galaxy situated horizontally overhead.
APOD: 2015 February 23 - The Milky Way Over the Arizona Toadstools
Explanation:
Which is older -- the rocks you see on the ground or the light you see from the sky?
Usually it’s the rocks that are older, with their origin sediments deposited well before light left any of the stars or nebulas you see in the sky.
However, if you can see, through a telescope, a distant galaxy far across the universe -- further than
Andromeda or spiral galaxy
NGC 7331 (inset) -- then you are seeing light even more ancient.
Featured here, the central disk of our
Milky Way Galaxy arches over Toadstool
hoodoos rock formations in northern
Arizona,
USA.
The unusual Toadstool rock caps
are relatively hard
sandstone
that wind has eroded more slowly than the softer sandstone underneath.
The green bands are
airglow, light emitted by the stimulated air in
Earth's atmosphere.
On the lower right is a time-lapse camera set up to capture the
sky rotating behind the picturesque foreground scene.
APOD: 2015 January 26 - The Milky Way over the Seven Strong Men Rock Formations
Explanation:
You may have heard of the
Seven Sisters in the sky,
but have you heard about the Seven Strong Men on the ground?
Located just west of the
Ural Mountains, the unusual
Manpupuner rock formations are one of the
Seven Wonders of Russia.
How these ancient 40-meter high
pillars formed is yet unknown.
The persistent photographer of
this featured image battled
rough terrain and uncooperative weather to capture these
rugged stone towers in winter at night, being finally successful in February of last year.
Utilizing the camera's time delay feature,
the photographer holds a flashlight in the foreground near one of the snow-covered
pillars.
High above, millions of stars shine down, while the band of our
Milky Way Galaxy crosses diagonally down from the upper left.
APOD: 2014 December 5 - Milky Way over Moon Valley
Explanation:
Our Milky Way
Galaxy arcs over a
desolate landscape
in this fantastic
panoramic
night skyview.
The otherworldly scene looks across the arid, eroded terrain of the
Valle de la Luna
in the Chilean Atacama desert.
Just along the horizon are lights from San Pedro, Chile,
as well as the small villages of Socaire and Toconao, and
a tortuous road from the city of Calama to San Pedro.
Taken on October 18th, the five panel mosaic
also features the four galaxies easily visible from our
fair planet's dark sky regions.
At the far left, satellite galaxies known as the
Large and Small Magellanic Clouds
are framed by their terrestrial namesakes.
Much fainter and at the right, beyond the Milky Way's central bulge,
is the Andromeda Galaxy.
The most distant in view,
Andromeda lies some 2.5 million light-years away.
APOD: 2014 October 31 - Milky Way over Devils Tower
Explanation:
A mysterious formation known as
Devils
Tower rises into
the dark above northeastern Wyoming's prairie landscape in this 16
frame panoramic view.
Seen against the night sky's thin, pale clouds and eerie green
airglow, star clusters and nebulae
of the Milky Way arc toward the galaxy's
central realm
at right.
Of course the scene contains the Milky Way's own
haunting and grisly visages
of
halloween, including
ghosts,
a flaming
skull,
a glowing eye and
a witch's broom.
To find them, slide your cursor over the picture or just
follow this link,
if you dare.
And have a safe and Happy Halloween!
APOD: 2014 October 3 - Aurora and Milky Way in a Little Sky
Explanation:
Stepping stones seem to lead to the Milky Way
as it stretches across this
little
sky.
Of course, the scene is really the northern hemisphere's
autumnal equinox night.
Water and sky are inverted by a top to bottom, around the horizon
stereographic projection
centered on the zenith above Lake
Storsjön in Jämtland, Sweden.
In the north the Milky Way arcs from east to west overhead as fall begins,
but the season is also a good time for viewing
aurora.
Geomagnetic storms
increase in frequency near
the equinox and produce remarkable displays of northern lights
at high latitudes, like the eerie greenish glow reflected
in this watery cosmos.
APOD: 2014 September 16 - Milky Way above Atacama Salt Lagoon
Explanation:
Galaxies, stars, and a serene reflecting pool combine to create this memorable land and skyscape.
The featured panorama is a 12-image mosaic taken last month from the
Salar de Atacama
salt flat in northern
Chile.
The calm water is
Laguna Cejar, a salty lagoon featuring a large central
sinkhole.
On the image left, the astrophotographer's fiancee is seen capturing the same photogenic scene.
The night sky is lit up with countless stars, the
Large and
Small Magellanic Cloud galaxies on the left,
and the band of our
Milky Way galaxy
running diagonally up the right.
The Milky Way
may appear to be causing havoc at the horizon, but those are just the
normal lights of a nearby town.
APOD: 2014 September 9 - An Aurora Cupcake with a Milky Way Topping
Explanation:
This sky looked delicious.
Double auroral ovals were captured above the town lights of
Östersund,
Sweden, last week.
Pictured above, the green ovals occurred lower to the ground than
violet
aurora rays above, making the whole display look a bit like a
cupcake.
To top it off, far in the distance, the
central band or our
Milky Way Galaxy
slants down from the upper left.
The auroras were caused by our Sun ejecting
plasma
clouds into the Solar System just a few days before, ionized particles that
subsequently impacted the
magnetosphere of the Earth.
Aurora
displays may continue this week as an
active sunspot group rotated into view just a few days ago.
APOD: 2014 August 27 - Milky Way over Yellowstone
Explanation:
The Milky Way was not created by an evaporating lake.
The colorful pool of water, about 10 meters across, is known as
Silex Spring and is located in
Yellowstone National Park in
Wyoming,
USA.
Illuminated artificially, the colors are caused by layers of
bacteria
that grow in the
hot spring.
Steam rises off
the spring, heated by a
magma chamber deep underneath known as the
Yellowstone hotspot.
Unrelated and far in the distance, the
central band of our
Milky Way Galaxy arches high overhead, a band lit by billions of stars.
The above picture is a 16-image panorama taken late last month.
If the Yellowstone hotspot causes another supervolcanic eruption as it did
640,000 years ago, a
large part of North America would be affected.
APOD: 2014 July 24 - ALMA Milky Way
Explanation:
This alluring all-skyscape was taken 5,100 meters above sea level,
from the Chajnantor Plateau
in the Chilean Andes.
Viewed through the site's rarefied atmosphere at about 50% sea level
pressure, the gorgeous Milky Way stretches through the scene.
Its cosmic rifts
of dust, stars, and nebulae are
joined by Venus, a brilliant morning star immersed
in a strong band of predawn Zodiacal light.
Still not completely dark
even at this high altitude,
the night sky's greenish cast is due to
airglow
emission from oxygen atoms.
Around the horizon the dish antenna units of
the Atacama Large Millimeter/submillimeter Array,
ALMA, explore the universe
at wavelengths over 1,000 times longer than visible light.
APOD: 2014 June 14 - New York to London Milky Way
Explanation:
Bright stars
of Sagittarius
and the center of our
Milky Way Galaxy
lie just off the wing of a Boeing 747 in
this astronomical travel photo.
The stratospheric scene was captured
earlier this month during a flight from
New York to
London,
11,000 meters above the Atlantic Ocean.
Of course the sky was clear and dark at that altitude,
ideal conditions for astronomical imaging.
But there were challenges to overcome
while looking out a passenger window of the aircraft
moving at nearly 1,000 kilometers per hour (600 mph).
Over 90 exposures of 30 seconds or less were attempted with a fast lens
and sensitive camera setting, using a small, flexible tripod and
a blanket to block reflections of interior lighting.
In the end, one 10 second long exposure resulted in this steady and
colorful example of
airborne astronomy.
APOD: 2014 March 29 - A Milky Way Dawn
Explanation:
As dawn broke
on March 27, the center of the Milky Way Galaxy
stood almost directly above the European Southern
Observatory's Paranal Observatory.
In the dry, clear sky of Chile's
Atacama desert, our galaxy's dusty central bulge is
flanked by Paranal's four 8 meter Very Large Telescope
units in this astronomical fisheye view.
Along the top, Venus is close to the eastern horizon.
The brilliant
morning star shines very near
a waning crescent Moon
just at the edge of one of the telescope structures.
Despite the bright pairing in the east, the Milky Way
dominates the scene though.
Cut by dust lanes
and charged with clouds of stars and glowing nebulae,
the center of our galaxy sprawls across the darker zenith
even as the deep blue sky grows brighter and buildings
still glint in moonlight.
APOD: 2014 February 12 - Rocket, Meteor, and Milky Way over Thailand
Explanation:
Can the night sky appear both serene and surreal?
Perhaps classifiable as serene in the
above panoramic image taken
last Friday are the faint lights of small towns glowing
across a dark foreground landscape of
Doi Inthanon National Park in
Thailand, as well as the
numerous stars glowing across a dark background starscape.
Also visible are the planet Venus and a band of
zodiacal light on the image left.
Unusual events are also captured, however.
First, the
central band of our
Milky Way Galaxy, while usually a
common sight, appears here to hover
surreally
above the ground.
Next, a fortuitous streak of a meteor was captured on the image right.
Perhaps the most unusual component is the bright spot just to the left of the meteor.
That spot is the plume of a rising Ariane 5 rocket,
launched a few minutes before from
Kourou,
French Guiana.
How lucky was the astrophotographer to capture the
rocket launch in his image?
Pretty lucky -- the image was not
timed to
capture the rocket.
Also lucky was how photogenic -- and perhaps
surreal -- the rest of the sky turned out to be.
APOD: 2013 September 2 - Milky Way Over Spain's Bardenas Reales
Explanation:
What's that below the Milky Way?
First, across the top of the
above image, lies the faint band that is our planet's sideways view
of the central disk of our home
Milky Way Galaxy.
The Milky Way band can be seen most
clear nights from just about anywhere on
Earth with a
dark sky.
What lies beneath is, by comparison, is a much less common sight.
It is the striking peak of Castildetierra, a rock formation located in
Bardenas Reales, a natural
badlands in northeast
Spain.
Standing 50 meters tall, the
rock spire
includes
clay and
sandstone
left over from thousands of years of
erosion by wind and water.
The astrophotographer waited months for the sky to appear just right -- and then took the 14 exposures that compose the
above image in a single night.
APOD: 2013 June 19 - Milky Way Over Crater Lake with Airglow
Explanation:
How many different astronomical phenomena have come together to create the above vista?
Several.
First, in the foreground, is
Crater Lake --
a caldera created by volcanism on planet Earth about 7,700 years ago.
Next, inside the lake, is water.
Although the origin of the water in the crater is melted snowfall,
the origin of water on Earth more generally is
unclear,
but possibly related to ancient Earthly-impacts of
icy bodies.
Next, the green glow in the sky is
airglow,
light emitted by atoms high in the Earth's atmosphere as they recombine
at night after being separated during the day by energetic sunlight.
The many points of light in the sky are stars, glowing by
nuclear fusion.
They are far above the atmosphere but
nearby to our Sun in the
Milky Way Galaxy.
Finally, the bright arch across the image is the
central band of the Milky Way,
much further away, on the average, than the nearby stars, and
shaped mostly by gravity.
Contrary to appearances, the Milky Way band glows by
itself and is not illuminated by the airglow.
The above image is a six-frame panorama taken during about two weeks ago in
Oregon,
USA.
APOD: 2013 April 29 - Milky Way and Stone Tree
Explanation:
What's that next to the Milky Way?
An unusual natural rock formation known as
Roque Cinchado or Stone Tree found on the
Spanish
Canary Island of
Tenerife.
A famous icon,
Roque Cinchado is likely a
dense plug of cooled volcanic magma that remains after softer surrounding
rock eroded away.
Majestically, the
central band of our
Milky Way Galaxy is visible
arcing across the right of the above
seven image panoramic mosaic taken during the summer of 2010.
On the far right is the
Teide volcano complete with a
lenticular cloud
hovering near its peak.
APOD: 2013 April 20 - Airglow, Gegenschein, and Milky Way
Explanation:
As far as the eye could see,
it was a dark night at
Las Campanas Observatory in the southern
Atacama desert of Chile.
But near local midnight on April 11, this mosaic of 3 minute long
exposures revealed a green, unusually intense,
atmospheric
airglow stretching over thin clouds.
Unlike aurorae powered by collisions with energetic charged particles
and seen at high latitudes, the airglow is
due
to chemiluminescence,
the production of light in a chemical reaction, and
found around the globe.
The chemical energy is provided by the Sun's extreme ultraviolet
radiation.
Like aurorae, the greenish hue of this airglow does originate
at altitudes of 100 kilometers or so dominated by
emission from excited oxygen atoms.
The gegenschein, sunlight reflected by dust
along the solar system's ecliptic plane was still visible on
that night, a faint bluish cloud just right of picture center.
At the far right, the Milky Way seems to rise from the mountain
top perch of the
Magellan telescopes.
Left are the OGLE project and
du Pont
telescope domes.
APOD: 2013 March 10 - Milky Way Panorama from Mauna Kea
Explanation:
Aloha and welcome to a breathtaking skyscape.
The dreamlike panoramic view looks out from the 4,200 meter volcanic
summit of Mauna Kea, Hawai'i,
across a layer of clouds toward a
starry night sky
and the rising Milky Way.
Anchoring the scene on the far left is the dome of the
Canada-France-Hawaii Telescope (CFHT), with
north star Polaris shining beyond the dome to the right.
Farther right, headed by bright
star Deneb,
the Northern Cross asterism
is embedded along the plane of the Milky Way as it peeks above the
horizon.
Both Northern Cross and
brilliant white
Vega
hang over a foreground grouping of cinder cones.
Near the center are the reddish nebulae, stars and dust clouds of
the central Milky Way.
Below, illumination from the city lights of Hilo creates
an eerie, greenish glow in the clouds.
Red supergiant
star Antares shines above the
Milky Way's central bulge while bright
Alpha Centauri
lies still farther right, along the dusty galactic plane.
Finally, at the far right is the large
Gemini North Observatory.
The compact group of stars known as the
Southern Cross is just
left of the telescope dome.
Need some help identifying the stars?
Just slide your cursor over the picture, or download this smaller,
labeled
panorama.
APOD: 2013 January 24 - ISS and the Summer Milky Way
Explanation:
Clouds on
a summer night
frame this sea and skyscape, recorded earlier
this month near Buenos Aires, Argentina.
But planet Earth's
clouds are not the only clouds on the scene.
Starry clouds and nebulae along the southern hemisphere's summer
Milky Way arc above the horizon, including
the dark Coal Sack
near the Southern Cross and the
tantalizing pinkish glow of the Carina Nebula.
Both the Large (top center) and Small Magellanic Clouds
are also in view, small galaxies in their own right and
satellites
of the Milky Way
up to 200,000 light-years distant.
Alpha star of the Carina constellation and second
brightest star in Earth's night,
Canopus
shines above about 300 light-years away.
Still glinting
in sunlight at an altitude of 400 kilometers,
the orbiting International Space Station traces a
long
streak through the single, 5 minute, star-tracking exposure.
APOD: 2012 December 12 - Milky Way Over Quiver Tree Forest
Explanation:
In front of a famous background of stars and galaxies lies some of Earth's more unusual trees.
Known as quiver trees, they are actually
succulent
aloe plants that can grow to tree-like proportions.
The quiver tree
name is derived from the historical usefulness of their hollowed branches as dart holders.
Occurring primarily in southern
Africa, the trees pictured in the
above 16-exposure composite are in
Quiver Tree Forest
located in southern Namibia.
Some of the tallest quiver trees
in the park are estimated to be about 300 years old.
Behind
the trees
is light from the small town of
Keetmanshoop,
Namibia.
Far in the distance,
arching across the background, is the majestic
central band of our
Milky Way Galaxy.
Even further in the distance, visible on the image left, are the
Large and
Small Magellanic Clouds,
smaller satellite galaxies of the Milky Way that are
prominent in the skies of
Earth's southern hemisphere.
APOD: 2012 November 2 - The Black Hole in the Milky Way
Explanation:
At the center of our Milky Way Galaxy,
a mere 27,000 light-years away,
lies a black hole with 4 million times the mass of the Sun.
Fondly known as Sagittarius A* (pronounced A-star),
the Milky Way's black hole is
fortunately mild-mannered compared
to the central black holes in
distant active galaxies, much
more calmly consuming material around it.
From time to time it does flare-up, though.
An outburst lasting several hours is captured in
this series of premier X-ray images
from the orbiting
Nuclear
Spectroscopic Telescope Array (NuSTAR).
Launched last June 13, NuSTAR is the first to provide
focused views
of the area surrounding Sgr A* at X-ray energies higher than
those accessible to Chandra and XMM observatories.
Spanning two days of NuSTAR observations,
the flare sequence is illustrated in the panels at the far right.
X-rays are generated in material heated to over 100 million
degrees Celsius, accelerated to nearly the speed of light as it
falls into the Miky Way's central black hole.
The main inset X-ray image
spans about 100 light-years.
In it, the bright white region represents the hottest material closest
to the black hole, while the pinkish cloud likely belongs to a
nearby supernova remnant.
APOD: 2012 October 20 - Zodiacal Light and Milky Way
Explanation:
Ghostly apparitions of two fundamental planes
in planet Earth's sky span this October all-sky view.
The scene was captured from a
lakeside campsite
under dark skies in northern Maine, USA.
In it, the plane of our
Milky Way Galaxy arcs above
faint airglow along the horizon.
Zodiacal light,
a band of dust scattering sunlight along the solar system's
ecliptic plane,
stretches almost horizontally
across the wide field and intersects the Milky way
near a point marked by bright planet Jupiter.
Right of Jupiter, past the
Pleiades star cluster,
is the brightening of the Zodiacal band known as the
Gegenschein,
also visible to the eye on that dark night.
Begirt with many a blazing star
and rising above the distant mountains,
Orion the hunter is
reflected in the lake's calm waters.
APOD: 2012 September 11 - Milky Way Over the Bungle Bungles
Explanation:
Which part of this picture do you find more interesting -- the land or the sky?
Advocates for the land might cite the beauty of the ancient domes of the
Bungle Bungle Range in
Western Australia.
These picturesque domes appear as
huge layered beehives
and are made of sandstones and
conglomerates deposited over 350 million years ago.
Advocates for the
sky
might laud the beauty of the
Milky Way's central band shown arching from horizon to horizon.
The photogenic
Milky
Way
band formed over 10 billion years ago and now
includes many well-known nebulae and bright stars.
Fortunately, you don't have to
decide
and can enjoy both together in
this beautiful 8-frame panorama taken from the dark skies of
Purnululu National Park
about two months ago.
APOD: 2012 August 14 - Perseid Meteors and the Milky Way
Explanation:
Where will the next Perseid meteor appear?
Sky enthusiasts who trekked outside for the Perseid meteor shower that peaked over the past few days
typically had this question on their mind.
Six meteors from this past weekend are
visible in the above stacked image composite, including one bright
fireball streaking along the band of the background Milky Way Galaxy.
All Perseid meteors appear to come from the
shower radiant in the
constellation of Perseus.
Early reports about
this year's Perseids indicate that as many as 100 meteors per hour were
visible from some dark locations during the peak.
The above digital mosaic was taken near
Weikersheim,
Germany.
APOD: 2012 August 1 - The Milky Way Over Monument Valley
Explanation:
You don't have to be at Monument Valley to see the Milky Way arch across the sky like this -- but it helps.
Only at Monument Valley
USA
would you see a
picturesque foreground
that includes these iconic rock peaks called
buttes.
Buttes are composed of hard rock left behind after
water
has eroded away the surrounding soft rock.
In the above image taken about two months ago, the closest butte on the left and
the butte to its right are known as
the Mittens, while
Merrick Butte
can be seen just further to the right.
High overhead stretches a band of diffuse light that is the central disk of our
spiral
Milky Way Galaxy.
The band of the Milky Way can be
spotted by almost anyone on
almost any clear night when
far enough from a city and
surrounding bright lights.
APOD: 2012 June 25 - Milky Way Over Piton de lEau
Explanation:
Sometimes, if you wait long enough for a clear and moonless night, the stars will come out with a vengeance.
One such occasion occurred earlier this month at the Piton de l'Eau on
Reunion Island.
In the foreground, surrounded by bushes and trees, lies a water filled volcanic crater serenely reflecting starlight.
A careful inspection near
the image center will locate
Piton des Neiges, the highest peak on the island,
situated several kilometers away.
In the background, high above the lake, shines the light of hundreds of stars, most of which are within 100 light years, right in
our stellar neighborhood.
Far in the distance,
arching
majestically
overhead,
is the central band of our home
Milky Way Galaxy, shining by the light of millions of stars each located typically thousands of light years away.
The astrophotographer reports
waiting for nearly two years for the sky and clouds to be just right to get the above shot.
APOD: 2012 June 18 - Milky Way Above Easter Island
Explanation:
Why were the statues on
Easter Island built?
No one is sure.
What is sure is that over 800 large stone statues exist there.
The Easter Island statues, stand, on the average, over
twice as tall as a person and have over 200 times as much mass.
Few specifics are known about the history or meaning of the
unusual statues,
but many believe that they were created about
500 years ago in the
images
of local leaders of a lost civilization.
Pictured above, some of the
stone
giants were illuminated in 2009
under the central band of our Milky Way Galaxy.
APOD: 2012 June 4 - Milky Way Galaxy Doomed: Collision with Andromeda Pending
Explanation:
Will our Milky Way Galaxy collide one day with its larger neighbor, the Andromeda Galaxy?
Most likely, yes.
Careful plotting of slight displacements of M31's stars relative to background galaxies on recent
Hubble Space Telescope images indicate that the center of M31 could be on a direct
collision course with the center of our home galaxy.
Still, the errors in sideways velocity appear sufficiently large to admit a
good chance that the central parts of the two galaxies will miss, slightly, but will become
close enough for their outer halos to become
gravitationally entangled.
Once that happens, the two galaxies will become bound,
dance around, and
eventually merge to
become one large
elliptical galaxy --
over the next few billion years.
Pictured above is an artist's illustration of the sky of a world in the distant future when the central parts of each galaxy begin to destroy each other.
The exact future of our Milky Way and the entire surrounding
Local Group of Galaxies
is likely to remain an active topic of research for years to come.
APOD: 2012 March 29 - Rocket Trails in the Milky Way
Explanation:
On March 27, five
sounding
rockets leapt into early morning skies from NASA's
Wallops
Flight Facility in Virginia.
Part of the Anomalous Transport Rocket EXperiment
(ATREX),
begining at 4:58 am EDT the
rockets launched consecutively
at 80 second intervals.
Releasing a chemical tracer they created luminous white clouds
within Earth's
ionosphere
at altitudes above 60 to 65 miles, swept along by the poorly understood
high-altitude jet stream.
(Not the same jet stream that airliners fly through at altitudes of 5
to 6 miles.)
Seen along
the mid-atlantic region of the United States,
the clouds drifted through starry skies,
captured in this clear photograph from East Point, New Jersey.
Looking
south toward the launch site, the tantalizing
celestial background includes the stars of Sagittarius, Scorpius, and
the more permanent faint, white, luminous clouds of
the Milky Way.
APOD: 2011 September 24 - Mangaia's Milky Way
Explanation:
From Sagittarius to
Carina, the Milky Way Galaxy
shines in this dark night sky
above planet Earth's lush island paradise
of Mangaia.
Familiar to denizens of the southern hemisphere,
the
gorgeous skyscape includes the bulging
galactic center at the upper left and bright stars
Alpha and Beta Centauri just right of
center.
About 10 kilometers wide, volcanic
Mangaia is
the southernmost of the Cook Islands.
Geologists estimate that at 18 million years old
it is the oldest island in the Pacific Ocean.
Of course, the Milky Way is somewhat older, with the galaxy's
oldest stars
estimated to be over 13 billion years old.
(Editor's note:
This
image holds the distinction of being selected as winner in
the Royal Observatory, Greenwich, Astronomy Photographer of the
Year competition in the Earth and Space category.)
APOD: 2011 July 25 - Milky Way Over Abandoned Kilns
Explanation:
What's that below the Milky Way?
Historic kilns.
Built in the 1870s in rural
Nevada,
USA to process local wood into
charcoal, the kilns were soon abandoned due to a town fire and flooding, but remain in good condition even today.
The above panorama is a digital conglomerate of five separate images taken in early June from the same location.
Visible above the unusual
kilns is a colorful star field, highlighted by the central band of our
Milky Way Galaxy appearing along a diagonal toward the lower right.
Many famous sites in our Galaxy are visible, including the
Pipe Nebula and the
Dark River to Antares,
seen to the right of the Milky Way.
The origin of the green mist on the lower left, however, is
currently unexplained.
APOD: 2011 July 10 - A Milky Way Band
Explanation:
Most bright stars in our
Milky Way Galaxy reside in a disk.
Since our Sun also resides in this disk, these stars
appear to us as a
diffuse band that circles the sky.
The above panorama of a
northern band of the
Milky Way's disk covers 90 degrees and is a
digitally created mosaic of several independent exposures.
Scrolling right will display the rest of this spectacular picture.
Visible are many
bright stars,
dark dust lanes,
red emission nebulae,
blue reflection nebulae, and
clusters of stars.
In addition to all this matter that we can see,
astronomers
suspect there exists even more
dark matter that we cannot see.
APOD: 2011 June 17 - Eclipsed Moon in the Milky Way
Explanation:
On June 15, the
totally eclipsed Moon was very dark,
with the Moon itself positioned on the sky toward the center
of our Milky Way Galaxy.
This simple panorama captures totality
from northern Iran in 8 consecutive exposures
each 40 seconds long.
In the evocative scene,
the dark of the eclipsed Moon
competes with the Milky Way's faint glow.
The tantalizing
red lunar disk lies just above
the bowl of the dark
Pipe Nebula, to the right of the glowing
Lagoon and Trifid nebulae
and the central Milky Way dust clouds.
At the far right,
the wide field is anchored by yellow Antares and
the colorful clouds of Rho Ophiuchi.
To identify other sights of the central Milky Way just slide your
cursor over the image.
The total phase of this
first lunar eclipse of 2011 lasted an
impressive 100 minutes.
Parts of the eclipse were
visible
from most of planet Earth, with
notable exceptions of North and Central America.
APOD: 2011 April 5 - The Milky Way Over Tenerife
Explanation:
Have you ever seen the band of our
Milky Way Galaxy?
Chances are you have never seen it like this --
nor could you.
In a clear sky from a dark location at the right time, a
faint band of light is visible across the sky.
This band is the disk of our
spiral galaxy.
Since we are inside this disk, the band appears to encircle the Earth.
The above spectacular picture of the Milky Way arch, however, goes where the unaided eye cannot.
The image is actually a deep digital fusion of nine photos that create a panorama fully 360 across.
Taken recently in
Teide National Park in
Tenerife,
Canary Islands,
Spain, the image includes the
Teide volcano, visible near the image center, behind a volcanic landscape that includes many large rocks.
Far behind these Earthly structures are many sky wonders
that are visible to the unaided eye, such as the band of the Milky Way, the bright
waxing Moon
inside the
arch, and the
Pleiades open
star cluster
(can you find it?).
The deep exposure also brings out many sky wonders normally beyond
human perception, many of which are labelled on the annotated image version, including
Barnard's Loop,
visible above as the half red ring below the
Milky Way band.
APOD: 2011 February 21 - Milky Way Over Switzerland
Explanation:
What's visible in the night sky during this time of year?
To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over
Neuchâtel,
Switzerland.
Visible in the foreground were the snow covered cliffs of the amphitheater shaped
Creux du Van, as well as distant trees, and town-lit clouds.
Visible in the night sky (at midnight) were galaxies including the
long arch of the central band of our
Milky Way Galaxy, the
Andromeda galaxy (M31), and the
Triangulum galaxy
(M33).
Star clusters visible included NGC 752,
M34,
M35,
M41,
the double cluster, and
the Beehive (M44).
Nebulas visible included the Orion Nebula
(M42),
NGC 7822,
IC 1396, the
Rosette Nebula,
the Flaming Star Nebula, the
California Nebula, the
Heart and
Soul Nebulas, and the
Pacman Nebula.
Rolling your cursor over the
above image will bring up labels for
all of these.
But the above
wide angle sky image captured even more sky wonders.
What other nebulas
can you find in the above image?
APOD: 2010 November 10 - Huge Gamma Ray Bubbles Found Around Milky Way
Explanation:
Did you know that our Milky Way Galaxy has huge bubbles emitting gamma rays from the direction of the galactic center?
Neither did anybody.
As the data from the Earth-orbiting
Fermi satellite began
accumulating over
the past two
years, however,
a large and unusual feature toward
our Galaxy's center became increasingly evident.
The two bubbles are visible together as the red and white spotted oval surrounding the center of the above all sky image,
released yesterday.
The plane of our Galaxy runs horizontally across the image center.
Assuming the bubbles emanate from our Galaxy's center, the scale of the bubbles is huge, rivaling the entire Galaxy in size, and spanning about 50,000
light years from top to bottom.
Earlier indications of the bubbles have been found on
existing all sky maps in the
radio,
microwave, and
X-ray.
The cause of the bubbles is
presently unknown, but will likely be researched for years to come.
APOD: 2010 November 1 - The Milky Way Over the Peak of the Furnace
Explanation:
On Reunion Island,
it is known simply as "The Volcano."
To others, it is known as the
Piton de la Fournaise, which is French for the Peak of the Furnace.
It is one of the
most active volcanoes
in the world.
The Volcano started a new eruption last month by spewing
hot lava
bombs
as high as 10 meters into the air from several vents.
Pictured above, the recent eruption was
caught before a star filled southern sky,
appearing somehow contained beneath the arching band of our
Milky Way Galaxy.
Also visible in the background sky is the
Pleiades
open star cluster, the
constellation of Orion, the
brightest star Sirius,
and the neighboring
Large and
Small Magellanic
Cloud galaxies. (Can you
find them?)
The Piton de la Fournaise erupted for months in 2006, and for days in 2007, 2008, and in January of 2010.
Nobody knows how long the
current eruption will last, or when The Volcano will erupt next.
APOD: 2010 August 23 - A Milky Way Shadow at Loch Ard Gorge
Explanation:
Have you ever seen the Milky Way's glow create shadows?
To do so, conditions need to be just right.
First and foremost, the sky must be relatively clear of clouds so that the
long band of the
Milky Way's central disk can be seen.
The surroundings must be very near to completely dark, with no bright
artificial lights visible anywhere.
Next, the
Moon cannot be anywhere above the horizon,
or its glow will dominate the landscape.
Last, the shadows
can best be caught on long camera exposures.
In the above image taken in
Port Campbell National Park,
Victoria,
Australia,
seven 15-second images of the ground and
de-rotated sky were digitally added to bring up the needed light and detail.
In the foreground lies
Loch Ard Gorge, named after a
ship that tragically ran aground in
1878.
The two rocks pictured are the remnants of a collapsed arch and are named Tom and Eva after the only two people who survived that
Loch Ard ship wreck.
A close inspection of the
water just before the rocks will show reflections and
shadows in light thrown by our
Milky Way galaxy.
Low clouds are visible moving through the serene scene in
this movie.
APOD: 2010 July 27 - The Milky Way Over Bryce Canyon
Explanation:
What are those strange rock structures?
They are towers and walls of sedimentary rock that are particularly plentiful in
Bryce Canyon in
Utah,
USA.
The rock columns may rise higher than 50 meters and are called
hoodoos.
On the far left is
Thor's Hammer,
perhaps the most famous
hoodoo.
The tall rock columns were carved, most typically, when a unusually dense cap of rock provided a layer of protection to rock underneath from rain-based
erosion.
In the above panoramic picture taken earlier this month and compressed horizontally, the foreground rocks were momentarily illuminated by a roving spotlight.
Visible in the background are a few
water clouds
a few kilometers away hovering over the nearby Earth.
Visible well beyond that are thousands of
individually discernible stars
averaging a few hundred
light years away in the nearby
Milky Way Galaxy.
Far in the distance lie billions of stars that are thousands of light years away and compose the faintly glowing arch that is the visible
central band of the flat disk of our Milky Way.
Over many years, wind and rain will eventually cause the tops of the
hoodoos to topple, whereafter the
underlying column will likely completely erode away.
APOD: 2010 July 9 - Microwave Milky Way
Explanation:
Seen from our edge-on perspective,
the Milky Way Galaxy sprawls
across the middle of this
false-color, all sky view.
The expansive microwave map is based on 1 year's worth
of data from instruments onboard the sky-surveying
Planck spacecraft.
Remarkably, the bright stripe of gas and dust clouds
along the galactic plane
and the galaxy's enormous arcing structures seen at
microwave energies
are hundreds or thousands of light-years away, while
the mottled regions at the top and bottom represent the Cosmic
Microwave Background (CMB) radiation,
some 13.7 billion
light-years
distant.
Left over from
the Big Bang,
fluctuations in the CMB reflect the origins
of structure in the evolving universe.
Analyzing the microwave data, Planck scientists plan to
separate the contributions of the Milky Way and CMB
radiation.
The work will ferret out the characteristics
of the CMB across the entire sky
and glean information about
the make up of our Milky Way Galaxy.
APOD: 2010 July 5 - The Milky Way Over Pulpit Rock
Explanation:
Can a picture of the sky be relaxing?
A candidate for such a picture might be
this image taken only last month from
Cape Schank,
Victoria,
Australia.
The frame is highlighted by a dreamlike lagoon,
two galaxies, and tens of thousands of stars.
The rock cropping on the left may appear from this angle like a
human head,
but the more famous rock structure is on the far right and known as
Pulpit Rock.
Across the top of the image runs a distant stream of
bright stars and dark dust that is part of the disk of our
spiral Milky Way Galaxy.
On the right, just above Pulpit Rock, is the Milky Way's small neighboring galaxy the
Small Magellanic Cloud (SMC).
The bright white object just to the
left of the SMC is a
globular cluster of stars in the
Milky Way known as 47 Tucana.
APOD: 2010 May 19 - Milky Way Over Ancient Ghost Panel
Explanation:
Long before
Stonehenge was built, well before the
Dead Sea Scrolls
were written, ancient artists painted life-sized figures on canyon walls in
Utah,
USA -- but why?
Nobody is sure.
The entire panel of figures,
which dates back about 7,000 years, is called the
Great Gallery and was found on the walls of
Horseshoe
Canyon in
Canyonlands National
Park.
The humans who painted them likely hunted
Mammoths.
The unusual fuzziness of largest figure led to
this mural section's informal designation as the
Holy Ghost Panel, although the intended attribution and societal importance of the figure are really unknown.
The above image was taken during a clear night in March.
The oldest objects in the above image are not the
pictographs, however, but the stars of our
Milky Way Galaxy far in the background, some of which are billions of years old.
APOD: 2010 March 22 - The Nearby Milky Way in Cold Dust
Explanation:
What shapes the remarkable dust tapestry of the nearby Milky Way Galaxy?
No one knows for sure.
The intricate structures, shown above,
were resolved in new detail recently in a wide region of the sky imaged in far infrared light by the
European Space Agency's
Planck satellite.
The above image is a digital fusion of three infrared colors: two taken at high resolution by Planck, while the other is an
older image taken by the now defunct
IRAS satellite.
At these colors, the sky is dominated by the faint
glow of very cold gas within only 500
light years of Earth.
In the above image, red corresponds to temperatures as cold as 10 degrees
Kelvin above absolute zero, while white corresponds to gas as warm at 40 Kelvins.
The pink band across the lower part of the image is warm gas confined to the
plane of our Galaxy.
The bright regions typically hold dense
molecular clouds that are
slowly collapsing to form stars,
whereas the dimmer regions are most usually
diffuse interstellar gas and
dust known as
cirrus.
Why these regions have
intricate filamentary shapes shared on both large and small scales remains a topic of research.
Future study of the origin and evolution of dust may help in the understanding the
recent history of our Galaxy as well as how
planetary systems
such as our Solar System
came to be born.
APOD: 2010 March 20 - Zodiacal Light Vs. Milky Way
Explanation:
Ghostly Zodiacal
light, featured
near
the center
of this remarkable panorama, is produced as sunlight is
scattered by dust in the Solar System's
ecliptic plane.
In the weeks surrounding the March
equinox (today at 1732
UT)
Zodiacal light is more prominent after sunset in the
northern hemisphere, and before sunrise in the south, when
the ecliptic makes a steep angle with the horizon.
In the picture, the narrow triangle of Zodiacal light extends
above the western horizon and seems to end at the lovely
Pleiades star cluster.
Arcing above the Pleiades are stars and nebulae
along the plane of our Milky Way Galaxy.
Recorded on March 10 from
Teide National Park on
the island of Tenerife, the vista is
composed of 4 separate pictures spanning over 180 degrees.
APOD: 2009 November 25 - All Sky Milky Way Panorama
Explanation:
If you could go far away from the Earth and look around the entire sky --
what would you see?
Such was the goal of the
All-Sky
Milky Way Panorama 2.0 project of Axel Mellinger.
Presented above
is the result: a
digital compilation of over 3,000
images comprising the highest resolution
digital panorama of the entire night sky yet created.
An interactive zoom version, featuring over 500 million pixels, can be found
here.
Every fixed astronomical object visible to the unaided eye has been imaged, including
every constellation,
every nebula, and
every star cluster.
Moreover, millions of individual stars are
also
visible, all in our
Milky Way Galaxy, and many a
thousand times fainter than a human can see.
Dark filaments of dust lace the
central band of our Milky Way Galaxy,
visible across the image center.
The satellite galaxies
Large and
Small Magellanic Clouds are visible on the lower right.
This was not the first time Dr. Mellinger has embarked on such a project:
the results of his first All-Sky Milky Way Panorama Project, taken using
photographic film, are visible
here.
APOD: 2009 October 16 - Herschel Views the Milky Way
Explanation:
With a 3.5 meter diameter mirror, larger than the Hubble
Space Telescope, Herschel is ESA's
new infrared
observatory.
The space-based telescope is named for
German-born British astronomer Frederick William
Herschel who
discovered infrared light
over 200 years ago.
In initial tests,
Herschel's cameras have combined to deliver
this spectacular view
along the plane of the Milky Way in
the constellation of the Southern Cross.
Spanning some 2 degrees the premier, false-color,
far-infrared view captures our galaxy's cold
dust clouds
in extreme detail, showing a remarkable,
connected maze of filaments and
star-forming regions.
These and planned future Herschel observations are intended to
unravel mysteries of star formation by surveying broad areas of the
galactic plane.
APOD: 2009 September 26 - Gigagalaxy Zoom: Milky Way
Explanation:
Our magnificent Milky Way Galaxy sprawls across this
ambitious all-sky panorama.
In fact, at 800 million pixels the full resolution mosaic strives
to show all the stars the eye can see in planet Earth's night sky.
Part of ESO's
Gigagalaxy Zoom
Project, the mosaicked images were recorded over several months of
2008 and 2009 at exceptional astronomical sites;
the Atacama Desert in the southern hemisphere
and the Canary Islands in the northern hemisphere.
Also capturing bright
planets and even a comet, the individual frames
were stitched together and mapped
into a single, flat, apparently seamless
360 by
180 degree view.
The final result is oriented so the plane of our galaxy
runs horizontally through the middle with the bulging
Galactic Center at image center.
Below and right of center are the Milky Way's satellite galaxies,
the Magellanic Clouds.
APOD: 2009 August 18 - The Milky Way Over the Badlands
Explanation:
Why take a picture of just the
Badlands when you can take one that also
shows the spectacular sky above it?
Just such a picture, actually a digital stitched panorama of four images,
was taken in late June near midnight, looking southwest.
In the foreground, the
unusual buttes of the Badlands Wall, part of the
Badlands National Park in
South Dakota,
USA, were momentarily illuminated by flashlight
during a long duration exposure of the background night sky.
The mountain-like buttes
visible are composed of soft rock that show sharp erosion features from wind and water.
The South Dakota Badlands also contain ancient beds rich with easy-to-find fossils.
Some fossils are over 25 million years old and hold clues to the evolutionary origins of the horse and the
saber-toothed tiger.
Bright Jupiter dominates the sky on the left just above the buttes,
while the spectacular
Milky Way Galaxy
runs down the image right.
APOD: 2009 July 29 - The Milky Way Over Devils Tower
Explanation:
Was Devils Tower once an explosive volcano?
Famous for its appearance in films such as
Close Encounters, the origin of
Devil's Tower in
Wyoming,
USA is still debated, with a leading hypothesis holding that it is
a hardened lava plume that probably never reached the surface to become a
volcano.
The lighter rock that once surrounded the dense
volcanic neck
has now eroded away, leaving the dramatic tower.
High above, the central band of the Milky Way galaxy arches across the sky.
Many notable sky objects are
visible, including dark strands of the
Pipe Nebula and the reddish
Lagoon Nebula to the tower's right.
Green grass and trees line the moonlit foreground, while clouds appear near the horizon to
the tower's left.
Unlike many other international landmarks, mountaineers are permitted to climb
Devils Tower.
APOD: 2009 May 19 - Sagittarius and the Central Milky Way
Explanation:
What does the center of our Milky Way Galaxy look like?
In visible light, no one knows!
It is not possible to see the
Galactic center in light our eyes are sensitive
to because the thick
dust in the
plane of our Galaxy obscures it.
If one
looks in the direction of
our Galaxy's center -
which is toward the
constellation of Sagittarius - many
beautiful wonders become apparent, though.
Large dust lanes and
star clouds dominate the picture.
As many as 30
Messier Objects
are
visible in the
above spectacular image mosaic, including all types of nebulas and star
clusters.
Two notable nebula include the
Lagoon Nebula (M8), a red
patch just above and to the right of center,
and slightly to its right is the red and blue
Trifid Nebula (M20).
APOD: 2009 May 1 - Lyrid Meteor and Milky Way
Explanation:
On April 22nd, the Lyrid Meteor Shower
visited planet Earth's sky,
an annual
shower produced as the Earth plows through dust from the tail of
comet Thatcher.
Usually Lyrid meteor watchers see only a drizzle.
Just a few meteors per hour stream away from the
shower's radiant point near
bright star Vega in the constellation Lyra.
But photographer Tony Rowell still managed to catch one bright
Lyrid meteor.
Recorded in early
morning hours, his well-composed
image looks
toward the south from White Mountains
of eastern California, USA.
During the time exposure, he briefly illuminated an
old mining cabin in
the region's Ancient
Bristlecone Pine Forest in the
foreground.
The rich starfields and dust clouds
of our own Milky Way galaxy stretch
across the background, along the
meteor's glowing trail.
APOD: 2009 February 19 - Mauna Kea Milky Way Panorama
Explanation:
Aloha and welcome to a breathtaking skyscape.
The dreamlike panoramic view looks out from the 4,200 meter volcanic
summit of Mauna Kea, Hawai'i,
across a layer of clouds toward a
starry night sky
and the rising Milky Way.
Anchoring the scene on the far left is the dome of the
Canada-France-Hawaii Telescope (CFHT), with
north
star Polaris shining beyond the dome to the right.
Farther right, headed by bright
star Deneb,
the Northern Cross asterism
is embedded along the plane of the Milky Way as it peeks above the
horizon.
Both Northern Cross and
brilliant white
Vega
hang over a foreground grouping of cinder cones.
Near the center are the reddish nebulae, stars and dust clouds of
the central Milky Way.
Below, illumination from the city lights of Hilo creates
an eerie, greenish glow in the clouds.
Red supergiant
star
Antares shines above the Milky Way's central bulge
while bright
Alpha
Centauri lies still farther right, along
the dusty galactic plane.
Finally, at the far right is the large
Gemini North Observatory.
The compact group of stars known as the
Southern Cross is just
left of the telescope dome.
Need some help identifying the stars?
Just slide your cursor over the picture, or download this smaller,
labeled
panorama.
APOD: 2009 February 12 - Zodiacal Light Vs. Milky Way
Explanation:
Two fundamental planes of planet Earth's sky compete
for attention in this remarkable wide-angle vista,
recorded on January 23rd.
Arcing above the horizon and into the night at the left
is a beautiful band of
Zodiacal Light - sunlight scattered by
dust
in the solar system's ecliptic plane.
Its opponent on the right is composed of the
faint stars, dust clouds, and nebulae along
the plane of our
Milky Way Galaxy.
Both celestial bands stand above the domes and towers of the
Teide Observatory
on the island of Tenerife.
Also out to play in the pristine, dark skies over the Canary Islands,
are brilliant Venus (lower left),
the distant
Andromeda Galaxy (near center),
and the lovely
Pleiades star cluster (top center).
Of course, seasoned skygazers might even spot
M33, the
California Nebula,
IC1805, and the
double star cluster of Perseus.
(Need some help? Just slide your cursor over the picture.)
APOD: 2009 January 27 - The Milky Way Over Mauna Kea
Explanation:
Have you ever seen the band of our Milky Way Galaxy?
In a clear sky from a dark location at the right time, a faint band of light becomes visible across the sky.
Soon after your eyes become
dark adapted,
you might spot the band for the first time.
It may then become obvious.
Then spectacular.
One reason for a growing astonishment might be the realization that this
fuzzy swath
contains billions of stars and is the disk of our
very own
spiral galaxy.
Since we are inside this disk, the
band appears to encircle the Earth.
Visible in the above image, high above in the night sky, the
band of the Milky Way Galaxy arcs.
The bright spot just below the band is the planet Jupiter.
In the foreground lies the moonlit caldera of the volcano
Haleakala,
located on the island of
Maui in
Hawaii,
USA.
A close look near the horizon will reveal light clouds and the dark but enormous
Mauna Kea volcano on the
Big Island of Hawaii.
If you have never seen the Milky Way band or recognized the
planet Jupiter, this year may be your chance.
Because 2009 is the
International Year of Astronomy,
an opportunity to look through a
window that peers deep into the universe
may be coming to a location near you.
APOD: 2008 December 11 - At the Center of the Milky Way
Explanation:
At the center of our Milky Way Galaxy lies a
supermassive black hole.
Once a controversial claim, this conclusion is now solidly based
on 16 years of observations
that map the orbits of 28 stars very near
the galactic center.
Using European Southern Observatory
telescopes and sophisticated
near infrared cameras, astronomers patiently measured the positions
of the stars over time, following one star, designated S2, through
a complete orbit as it came within about 1 light-day of the
center of the Milky Way.
Their results
convincingly show that S2 is moving under the influence of the
enormous gravity of a compact, unseen object -- a black hole
with 4 million times the mass
of
the Sun.
Their ability to track stars so close to the
galactic center
accurately measures the black hole's mass and also determines the
distance to the center to be 27,000 light-years.
This deep, near-infrared image shows the crowded inner 3
light-years of the central Milky Way.
Spectacular time-lapse animations of the stars orbiting
within light-days of the galactic center
can be found here.
APOD: 2008 September 5 - Milky Way Road Trip
Explanation:
In search of planets and the summer
Milky Way,
astronomer Tunç Tezel took an evening
road trip.
Last Saturday, after driving the winding road up
Uludag,
a mountain near Bursa, Turkey, he was rewarded by this beautiful
skyview to the south.
Near the center, bright planet Jupiter outshines
the city lights below and the stars of the constellation
Sagittarius.
Above the mountain peaks, an arcing
cloud bank seems to lead to the Milky Way's own
cloudy apparition plunging into the distant horizon.
In Turkish, Uludag
means Great Mountain.
Uludag was known in
ancient times
as the Mysian Olympus.
APOD: 2008 July 29 - The Milky Way Over Ontario
Explanation:
Sometimes, after your eyes adapt to the dark, a spectacular sky appears.
Such was the case earlier this month over
Ontario,
Canada,
when part of a spectacular sky also became visible in a reflection off a lake.
To start, the brightest objects visible are bright stars and the
planet Jupiter, seen as the brightest spot on the upper left.
A distant town appears as a diffuse glow over the horizon.
More faint still, the disk of the
Milky Way Galaxy
becomes apparent as a dramatic diffuse
band
across the sky that seems to crash into the horizon far in the distance.
In the foreground, a picturesque landscape includes
trees, a lake, and a
stone wall.
Finally, on this serene night in July when the lake water was unusually calm,
reflections appear.
Visible in the lake are not only reflections of several bright stars, but part of the
Milky Way band itself.
Careful inspection of the image will reveal, however, that bright stars leave small trails in the lake reflections that do not appear in the
sky above.
The reason for this is because the above image is actually a
digital composite of time-consecutive
exposures from the same camera.
In the first set of exposures, sky images were co-added with slight
rotations to keep the stars in one place.
APOD: 2008 June 6 - Two-Armed Spiral Milky Way
Explanation:
Gazing out from within
the Milky Way, our own galaxy's true structure is difficult to discern.
But an
ambitious survey effort with the
Spitzer Space Telescope now
offers convincing evidence
that we live in a large galaxy distinguished by two main
spiral arms
(the Scutum-Centaurus and Perseus arms)
emerging from the ends of a large central bar.
In fact, from a vantage point that viewed our galaxy
face-on,
astronomers in distant galaxies
would likely see
the Milky Way
as a two-armed barred spiral
similar to this
artist's illustration.
Previous investigations have identified
a smaller central barred structure and four spiral arms.
Astronomers still
place the Sun about a third of the way in from
the Milky Way's outer edge, in a minor arm called
the Orion Spur.
To locate the Sun and identify the Milky Way's newly mapped features,
just place your cursor over the image.
APOD: 2008 June 5 - Spitzer's Milky Way
Explanation:
The Spitzer Space Telescope's
encompasing infrared view of
the plane of our Milky Way Galaxy is hard to
appreciate in just
one picture.
In fact, more than 800,000 frames of data from Spitzer's
cameras have now been pieced together in an
enormous mosaic
of the galactic plane - the
most detailed infrared picture
of our galaxy ever made.
The small portion seen here spans nearly 8 degrees, roughly the
apparent
width of your fist held at arms length, across
the galaxy's center.
The full mosaic is 120 degrees wide.
Highlighted
in the false-color presentation are curving green
filaments of light from complex molecules - polycyclic aromatic
hydrocarbons
(PAHs) - that on Earth are the common, sooty
products of incomplete combustion.
The PAHs are found in
star
forming regions, along with reddish emission
from graphite
dust
particles.
Blue specks throughout the picture are individual Milky Way stars.
APOD: 2008 May 3 - Alborz Mountain Milky Way
Explanation:
Snow-capped stratovolcano
Mt. Damavand climbs to 5,670 meters
(18,598 feet) near the left edge in this panoramic view of
the world at
night.
In the sky to the left of Damavand's peak are the stars of the
Big Dipper in Ursa Major.
Pan to the right and your gaze will sweep across the arch of
our Milky Way Galaxy above the
Alborz Mountain Range
bordering the Caspian Sea.
Near the center of the panorama, recorded in the predawn
hours of April 4th, bright stars
Deneb and
Altair
lie close to the curve of the Milky Way, above the glow of
the Haraz valley.
Farther right, brilliant Jupiter dominates the sky
near the stars, nebulae, and dark dust clouds toward the
bulging galactic center.
Finally, the horizon glow at the right edge,
below bright yellowish giant star
Antares,
is from the city of Damavand, named for the legendary
mountain peak.
APOD: 2008 January 4 - The Milky Way at 5000 Meters
Explanation:
Climb up to 5000 meters (16,500 feet) above sea level, near
Cerro Chajnantor
in the northern
Chilean Andes,
and your night sky could encompass this cosmic vista.
Recorded from that
high and dry
locale, the spectacular fish-eye image features the myriad stars
and sprawling dust clouds of our
Milky Way Galaxy.
The direction toward the
center of the Galaxy is near the zenith
and center of the picture, but the
Galactic Center itself is hidden
from view, located far behind the obscuring dust.
Brilliant Jupiter rules this scene just above the
Milky Way's
central bulge with the noticeably fainter, yellowish,
giant star
Antares
to its right.
Small and faint, near the right edge of the picture is
one of the Milky Way's many
satellite
galaxies, the
Small Magellanic Cloud.
APOD: 2007 September 30 - A Milky Way Band
Explanation:
Most bright stars in our
Milky Way Galaxy reside in a disk.
Since our Sun also resides in this disk, these stars
appear to us as a
diffuse band that circles the sky.
The above panorama of a
northern band of the
Milky Way's disk covers 90 degrees and is a
digitally created mosaic of several independent exposures.
Scrolling right will display the rest of this spectacular picture.
Visible are many
bright stars,
dark dust lanes,
red emission nebulae,
blue reflection nebulae, and
clusters of stars.
In addition to all this matter that we can see,
astronomers suspect there exists even more
dark matter that we cannot see.
APOD: 2007 May 25 - Jupiter, Vesta, and the Milky Way
Explanation:
In this gorgeous skyscape, gas giant Jupiter
along with the stars and cosmic dust clouds
of the Milky Way
hang over the southern horizon in the
early morning hours as seen from Stagecoach, Colorado, USA.
Recorded on Thursday, Jupiter is the brightest object near picture
center.
Along with the stunning Milky Way, Jupiter is hard to miss,
but a
careful
inspection of the view also reveals
main belt
asteroid Vesta.
Of all the asteroids
Vesta is the brightest and
is now just bright enough to be visible to the naked eye
from locations with very dark, clear skies.
Vesta (as well as Jupiter) appears relatively
bright now because it is near opposition, literally opposite the Sun
in planet Earth's sky and closest to Earth in its orbit.
For Vesta, this opposition
offers the best viewing in many years.
The year 2007 also
coincides
with the 200th anniversary of
the asteroid's
discovery.
Starting late next month, NASA plans to launch the
Dawn mission intended
to explore Vesta (and Ceres) and the main asteroid belt.
APOD: 2007 May 17 - The Milky Way Near the Southern Cross
Explanation:
The glow of the southern Milky Way
and the well-known
Southern Cross
are featured in this colorful skyscape
recorded in April over La Frontera, Chile.
The Southern Cross
(Crux)
itself is at the right of the
20 degree wide field of view, topped by bright,
yellowish star
Gamma Crucis.
A line from Gamma Crucis through the blue
star at the bottom of the cross, Alpha Crucis,
points toward the south celestial pole.
Against faint Milky Way starlight, the dark expanse of the
Coal
Sack Nebula lies just left of the cross,
while farther left along the Milky Way are the bright stars
Hadar
and
Rigil
Kentaurus, also known as
Beta and Alpha
Centauri.
Blazing in the lower left, Alpha Cen is the closest star
to the Sun, a mere 4.3 light-years distant.
In fact, yellowish Alpha Cen is
actually a triple star
system that includes a sun-like star.
Seen
from Alpha Cen, our own Sun would be a bright yellowish
star in the otherwise recognizable constellation Cassiopeia.
APOD: 2006 August 1 - The Milky Way over Utah
Explanation:
If sometimes it appears that the entire
Milky Way Galaxy
is raining down on your head, do not despair.
It happens twice a day.
As the Sun rises in the East,
wonders of the night sky
become less bright than the
sunlight scattered by our own
Earth's atmosphere, and so fade from view.
They will only rotate
back into view when the Earth again eclipses our bright Sun at dusk.
This battle between heaven and Earth was
captured dramatically over a rock formation at
Capitol Reef National Park
Utah,
USA in 2003 May.
Dark dust,
millions of stars, and bright
glowing red gas highlight the
plane of our
Milky Way Galaxy,
which lies on average thousands of
light years behind
Earth's mountains.
APOD: 2005 December 16 - GLIMPSE the Milky Way
Explanation:
Scroll right and gaze through the dusty plane of our
Milky Way Galaxy in
infrared light.
The cosmic panorama
is courtesy of the
Galactic Legacy Infrared Mid-Plane Survey Extraordinaire
(GLIMPSE)
project and the
Spitzer
Space Telescope.
The galactic
plane itself runs through the middle
of the false-color view that spans nine degrees
(about 18 full moons)
across the southern constellation Norma.
Spitzer's infrared cameras see through much of the galaxy's
obscuring dust revealing many new star clusters as well as
star forming regions (bright white splotches) and hot
interstellar
hydrogen gas (greenish wisps).
The pervasive red clouds are emission from dust and
organic molecules,
pocked with holes and bubbles blown by
energetic outflows from
massive stars.
Intensely dark patches are regions of dust too dense
for even Spitzer's
infrared vision
to penetrate.
APOD: 2005 October 23 - At the Center of the Milky Way
Explanation:
At the center of our
Milky
Way Galaxy lies a black hole with
over 2 million times the mass of the Sun.
Once a controversial claim, this
astounding conclusion
is now virtually inescapable and based on observations of
stars orbiting
very near the galactic center.
Using one of the Paranal
Observatory's very large telescopes
and a sophisticated infrared camera,
astronomers
patiently followed the orbit of a particular star,
designated S2, as it came within about
17
light-hours of the center of the Milky Way
(about 3 times the radius of Pluto's orbit).
Their results
convincingly show that S2 is moving
under the influence of the enormous gravity of an
unseen object that must be extremely compact -- a
supermassive black hole.
This deep near-infrared
image shows the crowded inner 2
light-years of the Milky Way with the exact position of the
galactic center indicated by arrows.
The ability to track stars so close to the
galactic center
can accurately
measure the black hole's mass and perhaps
even provide an unprecedented test of Einstein's
theory of gravity
as astronomers watch a star orbit a
supermassive black hole.
APOD: 2005 October 4 - The Milky Way in Stars and Dust
Explanation:
The disk of our Milky Way Galaxy is home to hot nebulae, cold dust, and billions of stars.
This disk can be seen from a dark location on Earth as a
band of diffuse light
across the sky.
This band crosses the sky in dramatic fashion in the
above series of wide angle sky exposures from
Chile.
The deepness of the exposures also brings to light a vast network of complex
dust filaments.
Dust is so plentiful that it obscures our
Galaxy's center in visible light,
hiding its true direction until
discovered by other means early last century.
The Galactic Center, though, is
visible above as the thickest part of the disk.
The diffuse glow comes from billions of older, fainter stars like
our Sun,
which are typically much older than the dust or any of the nebulae.
One particularly photogenic area of darkness is the
Pipe Nebula visible above the Galactic Center.
Dark dust is not the
dark matter than dominates our Galaxy -- that
dark matter remains in a form
yet unknown.
APOD: 2005 August 25 - Barred Spiral Milky Way
Explanation:
A recent survey of stars
conducted with the Spitzer
Space Telescope is convincing astronomers that our
Milky Way Galaxy is not just your ordinary
spiral galaxy anymore.
Looking out from within
the Galaxy's disk, the true structure of
the
Milky Way is difficult to discern.
However, the penetrating infrared
census of about 30 million stars indicates that the Galaxy is
distinguished by a very large central bar some 27,000 light-years long.
In fact, from a vantage point that viewed our galaxy face-on,
astronomers in distant galaxies
would likely see a striking barred
spiral galaxy suggested
in this artist's illustration.
While previous investigations have
identified
a small central
barred structure, the new results indicate that the Milky Way's
large bar would make about a 45 degree angle with a line
joining the Sun and the Galaxy's center.
DON'T PANIC ...
astronomers still
place the Sun beyond the central
bar region, about a third of the way in from
the Milky Way's
outer edge.
APOD: 2005 August 15 - Perseid Meteors and the Milky Way
Explanation:
Where will the next Perseid meteor appear?
Sky enthusiasts who trekked outside for the
Perseid meteor shower that peaked over the past few days
typically had this question on their mind.
The above movie, where the time-line has been digitally altered, captures part of that very mystery.
Eight meteors from the night of August 12 and
the morning of
August 13 have been identified in the movie so far, seven of which are
Perseids.
Can you identify the non-Perseid meteor?
Since all Perseid meteors appear to come from the
constellation of Perseus, the non-Perseid meteor is the one that streaks
in a different direction.
Early reports are that
this year's Perseids were unfortunately a bit disappointing.
The above digital mosaic was taken from
Alsace,
France, with the photogenic
band of our
Milky Way Galaxy far in the background.
APOD: 2005 June 5 - A Milky Way Band
Explanation:
Most bright stars in our
Milky Way Galaxy reside in a disk.
Since our Sun also resides in this disk, these stars
appear to us as a
diffuse band that circles the sky.
The above panorama of a
northern band of the
Milky Way's disk covers 90 degrees and is a
digitally created mosaic of several independent exposures.
Scrolling right will display the rest of this spectacular picture.
Visible are many
bright stars,
dark dust lanes,
red emission nebulae,
blue reflection nebulae, and
clusters of stars.
In addition to all this matter that we can see,
astronomers suspect there exists even more
dark matter that we cannot see.
APOD: 2005 January 4 - Milky Way Illustrated
Explanation:
What does our Milky Way Galaxy look like from afar?
Since we are stuck inside, and since opaque
dust truncates our view in
visible light, nobody knows for sure.
Drawn above, however, is a good guess based on many different types of observations.
In the Milky Way's center
is a very bright core region centered on a
large black hole.
The Milky Way's bright
central bulge
is now thought to be an
asymmetrical bar
of relatively old and red stars.
The outer regions are where the
spiral arms
are found, dominated in appearance by
open clusters
of young, bright, blue stars, by red
emission nebula, and by dark dust.
The spiral arms reside in a disk dominated in mass by relatively dim stars and
loose gas composed mostly of
hydrogen.
What is not depicted is a huge spherical halo of invisible
dark matter that dominates the mass of the
Milky Way
as well as the motions of stars away from the center.
APOD: 2003 August 25 - The Northern Milky Way
Explanation:
Many of the stars in our home
Milky Way Galaxy appear together as a dim band
on the sky that passes nearly over the Earth's
north and south poles.
Pictured above is the part of
our Galaxy that passes
closest over the north pole.
Placing your cursor over the image will bring up the names of several constellations and
bright stars.
The diffuse white Galaxy glow is created by billions of stars,
while red patches are large
emission nebulas,
usually marking areas where bright stars have recently formed.
In the north, all of the
lights visible at night and all lights that created
this image were emitted within the past few thousand years
from within the Milky Way Galaxy -- except one.
On the upper right is a small faint patch designated M31, the
Andromeda Galaxy.
M31 is a spiral galaxy similar to our
Milky Way but so distant it emits the oldest light distinguishable by the unaided eye --
light that takes over two million years to reach us.
APOD: 2003 July 12 - X-Ray Milky Way
Explanation:
If you had x-ray vision,
the center regions
of our Galaxy would not be hidden from
view by the immense cosmic dust clouds
opaque to visible light.
Instead,
the Milky Way
toward Sagittarius might look something
like this stunning mosaic
of images from the orbiting
Chandra Observatory.
Pleasing to look at, the gorgeous false-color
representation of
the x-ray data shows
high energy x-rays in blue, medium energies in green,
and low energies in red.
Hundreds of white dwarf stars,
neutron stars, and black holes immersed in a
fog of multimillion-degree gas are included in the
x-ray vista.
Within the white patch at the image center lies
the Galaxy's central supermassive black hole.
Chandra's sharp
x-ray vision will likely lead to a new
appreciation of our Milky Way's most active neighborhood
and has already indicated that the hot gas itself may
have a temperature of a mere 10 million degrees Celsius
instead of 100 million degrees as previously thought.
The full mosaic is composed of 30 separate images and covers
a 900 by 400 light-year swath
at
the galactic center.
APOD: 2003 June 3 - The Milky Way Behind an Eclipsed Moon
Explanation:
What's behind the Moon? Each month,
our Moon passes in front of --
and outshines -- many an interesting star field.
Exceptions occur during a
new Moon and during a
total eclipse.
In the background of a new
Moon
is usually the Sun, an even brighter orb that even
more easily outshines everything behind it, except during a
total solar eclipse.
Even the longest total solar eclipse
lasts just a few minutes, while the
Sun's corona still remains bright.
During a total lunar eclipse,
however, the full Moon
dims and a majestic star field may present itself for an hour or more.
Such was the case during the middle of last month,
when a rare glimpse of an eclipsed Moon superposed in front of the disk of our home
Milky Way Galaxy was captured.
Although fully in the Earth's shadow, the eclipsed Moon is still the
brightest object on the right.
The above image was captured during sub-zero weather from the
Teide 2003 expedition to
Mirador del Pico Viejo, a mountain in the
Canary Islands,
Spain, off the northwest coast of
Africa.
APOD: 2002 September 23 - The Milky Way Over the French Alps
Explanation:
Have you ever seen the
band of our
Milky Way Galaxy?
Chances are you have never seen it like this --
nor could you.
In a clear sky from a dark location at the right time, a
faint band of light is visible across the sky.
This band is the disk of our
spiral galaxy.
Since we are inside this disk, the band appears to encircle the Earth.
The above spectacular picture is a bit of a
digital trick, though.
A first shot was taken in July 2000 with the camera
counter-rotating from the Earth
so that the stars appear fixed.
This allowed a long exposure from which a great
amount of detail could emerge from the
background star field.
Later, after moonrise,
a much shorter image was taken from the same location
catching details of the French Alps near
Mount Blanc, the
highest mountain in
Western Europe.
Reflections in the water were later enhanced digitally.
APOD: 2002 January 10 - X-Ray Milky Way
Explanation:
If you had x-ray vision,
the center regions
of our Galaxy would not be hidden from
view by immense cosmic dust clouds
opaque to visible light.
Instead,
the Milky Way
toward Sagittarius might look something
like this stunning mosaic
of images from the orbiting
Chandra Observatory.
Pleasing to look at, the gorgeous false-color
representation of
the x-ray data shows
high energy x-rays in blue, medium energies in green,
and low energies in red.
Hundreds of white dwarf stars,
neutron stars, and black holes immersed in a
fog of multimillion-degree gas are included in the
x-ray vista.
Within the white patch at the image center lies
the Galaxy's central supermassive black hole.
Chandra's sharp
x-ray vision will likely lead to a new
appreciation of our Milky Way's most active neighborhood
and has already indicated that the hot gas itself may
have a temperature of a mere 10 million degrees Celsius
instead of 100 million degrees as previously thought.
The full mosaic is composed of 30 separate images and covers
a 900 by 400 light-year swath
at
the galactic center.
APOD: 2001 July 12 - NGC 1850: Not Found in the Milky Way
Explanation:
A mere 168,000 light-years distant, this large, lovely cluster of
stars, NGC 1850,
is located near the outskirts of the central
bar structure in our neighboring galaxy, the
Large
Magellanic Cloud.
A first glance
at
this Hubble Space Telescope
composite
image suggests that
this cluster's size and shape are reminiscent of the ancient globular
star clusters which roam our own
Milky Way Galaxy's halo.
But NGC 1850's stars are young ... making it a type
of star cluster
with no known counterpart
in the Milky Way.
NGC 1850 is also a double star cluster, with a second, compact
cluster of stars visible here below and to the right of
the large cluster's central region.
Stars in the large cluster are estimated to be
50 million
years
young, while stars in the compact cluster are
younger still, with an age of about 4 million years.
In fact, the smaller cluster
contains T-Tauri
stars, thought
to be low mass, solar-type stars still
in the
process of formation.
The glowing nebula at the left, like the
supernova remnants in our own galaxy,
testifies to violent stellar explosions,
indicating short-lived massive stars
were also present
in NGC 1850.
APOD: 2001 June 27 - Moonlight, Mars and Milky Way
Explanation:
Aloha
and welcome to a breath-taking skyscape.
In this celestial scene,
a four day old Moon illuminates a dreamlike foreground while
bright planet Mars
(above center) rules and
the
Milky Way's cosmic clouds of stars and dust seem to stretch
from horizon to horizon.
The picture was taken on May 27th from what may be the best
amateur astronomy observing site
on planet Earth, near the
Mauna Kea, Hawai'i
Visitor Center, 9,600 feet above sea level.
Remarkable in the volcanic foreground are moonlit clouds and
an "ahu hoku" - a star marker or star altar - built up of rocks
topped with a white piece of coral gently glowing in the moonlight.
Now near its closest approach in 13 years,
Mars still lingers between the
Milky Way constellations of
Sagittarius and Scorpius.
High above the horizon by midnight,
the Red Planet is
exceptionally well placed for
earthdwellers to admire it.
Astrophotographer
Barney Magrath
comments that this splendid sky view
represents one of the joys of
photography itself.
When making the time exposure he did not realize that the
ahu hoku would become such a beautiful element in his celestial
composition.
APOD: 2000 June 18 - The Milky Way Near the Southern Cross
Explanation:
This breathtaking patch of sky would be above you were you
to stand at the
South Pole of the Earth.
Just above and to the right of
this photograph's center
are the four stars that mark the
boundaries of the famous
Southern Cross.
At the top of this constellation, also known as
The Crux, is the orange star
Gamma Crucis.
The
band of stars, dust, and gas
crossing the middle of the photograph is part our
Milky Way Galaxy.
In the very center of the photograph is the dark
Coal Sack Nebula,
and the bright nebula on the far right is the
Carina Nebula.
The Southern Cross is such a famous constellation that it is
depicted on the
national flag of Australia.
APOD: 2000 January 30 - The Milky Way in Infrared
Explanation:
At night, from a dark location, part of the clear sky looks
milky.
This unusual swath of dim light is generally visible during
any month and from any location.
Until the invention of the telescope,
nobody really knew what the "Milky Way" was.
About 300 years ago telescopes caused a startling revelation: the Milky Way was made of
stars.
Only 70 years ago,
more powerful telescopes
brought the further revelation that the
Milky Way is only one galaxy among many.
Now telescopes in space allow yet deeper understanding.
The
above picture was taken by the
COBE satellite
and shows the plane of our Galaxy in infrared light. The thin disk of our home
spiral galaxy
is clearly apparent, with stars appearing white and
interstellar dust appearing red.
APOD: December 14, 1999 - High Velocity Clouds and the Milky Way
Explanation:
Where are these gas clouds going so quickly?
High velocity clouds (HVCs) of gas
have been seen for decades but their origins and
destinations have remained mysterious.
Recent measurements have now placed at least
one of these clouds in the halo of our
Milky Way Galaxy, while other measurements
have determined the relative abundance of cloud elements.
Of the two clouds measured, each appears to have a
chemical abundance consistent with a different origin.
One HVC has been measured to have very few heavy elements
("low metallically") compared to neighboring stars,
while another HVC has been inferred to have a
heavy element abundance more typical of neighboring stars.
Hypotheses are therefore being investigated that
some HVCs are local gas remnants being
pushed away from our Galaxy by
supernova explosions, while other
HVCs are ancient
dwarf galaxy
remnants falling toward our Galaxy.
The latter possibility is particularly
interesting as it might help explain how our
Galaxy can continue to
make stars at the observed rate.
Fast moving HVCs are circled in the above false-color mosaic.
APOD: October 9, 1999 - The Frothy Milky Way
Explanation:
Astronomers have discovered that looking at dust along
the plane of our Milky Way Galaxy
is a bit like looking into a frothy glass of beer.
The dust between stars
in our galaxy appears to be arranged
like a foam with bubbles and voids -- churned by
shocks and winds generated
as stars cycle through their lives.
This processed
infrared image, based on
data from NASA's IRAS satellite, maps the radiation from
the edges of galactic dust clouds and reveals the complex distribution.
The image covers an area of about 40x60
degrees centered on the
galactic plane near the Cygnus region.
It shows bright bubble-shaped
and arc-like dust clouds around the
supernova remnants and
starbirth regions embedded in the galactic disk.
APOD: February 24, 1999 - A Milky Way Band
Explanation:
Most bright stars in our
Milky Way Galaxy reside in a disk.
Since our Sun also resides in this disk, these stars
appear to us as a
diffuse band that circles the sky.
The above panorama of a
southern band of the
Milky Way's disk was taken from
Australia.
A 40-minute exposure was used, and the colors were digitally enhanced.
Visible are many
bright stars,
dark dust lanes,
red emission nebulae,
blue reflection nebulae, and
clusters of stars.
In addition to all this matter that we can see,
astronomers suspect there exists even more
dark matter that we cannot see.
APOD: November 26, 1998 - Meteor Milky Way
Explanation:
The bold, bright
star patterns of Orion (right) are a
familiar sight to even casual skygazers.
But this gorgeous color photo also features a subtler
spectacle - the faint stars
of the Milky Way.
A broad region of
the Milky Way
runs vertically through the picture
with the striking
red Rosette Nebula in bloom left of center.
Cutting across this dim, diffuse band of stars which lie along
the plane of our Galaxy is a meteor streak.
It seems to pass just under
the red-orange giant star Betelgeuse at
Orion's shoulder.
Astrophotographer
Jeff Medkeff recorded
this and other beautiful time exposures from
a dark sky countryside southeast of Sierra Vista, Arizona USA,
during
November's Leonid
meteor shower.
APOD: August 17, 1998 - Comet Hyakutake and the Milky Way
Explanation:
Two years ago, the
Great Comet of 1996,
Comet Hyakutake,
inched across our northern sky during its
long orbit around the
Sun. Visible above as the
bright spot with the
faint tail
near the picture's center,
Comet Hyakutake
shares the stage with part of the central band of the
Milky Way Galaxy,
prominent in the picture's upper right. Also visible are
Antares,
the bright orange star in the upper right, Arcturus, the bright star on the lower left, and the
Pipe Nebula,
which is perhaps harder to find.
Comet Hyakutake's
unusually close approach to the
Earth allowed astronomers
to learn many things, including that
comets can emit much X-ray light.
APOD: May 23, 1998 - 7,000 Stars And The Milky Way
Explanation:
This panorama
view of the sky
is really a drawing.
It was made in the 1950s under the supervision
of astronomer Knut Lundmark at the
Lund Observatory in Sweden.
To create the picture, draftsmen used
a mathematical distortion to map
the entire sky onto an oval shaped image with
the plane of our Milky Way Galaxy
along the center and the north galactic
pole at the top.
7,000 individual stars are shown as white dots, size
indicating brightness.
The "Milky Way" clouds, actually the combined
light of dim, unresolved stars in the
densely populated galactic plane, are
accurately painted on, interrupted by
dramatic dark dust lanes.
The overall effect is photographic in quality and represents the visible
sky.
Can you identify any familiar
landmarks or constellations?
For starters,
Orion
is at the right edge of the picture, just below the galactic plane
and the Large and
Small Magellanic Clouds are visible as
fuzzy patches in the lower right quadrant.
APOD: May 2, 1998 - The Frothy Milky Way
Explanation:
Astronomers have discovered that looking at dust along
the plane of our Milky Way Galaxy
is a bit like looking into a frothy glass of beer.
The dust between stars
in our galaxy appears to be arranged
like a foam with bubbles and voids -- churned by
shocks and winds generated
as stars cycle through their lives.
This processed
infrared image, based on
data from NASA's IRAS satellite, maps the radiation from
the edges of galactic dust clouds and reveals the complex distribution.
The image covers an area of about 40x60 degrees centered on the
galactic plane near the Cygnus region.
It shows bright bubble-shaped
and arc-like dust clouds around the
supernova remnants and
starbirth regions embedded in the galactic disk.
APOD: February 16, 1998 - Sagittarius Dwarf to Collide with Milky Way
Explanation:
Our Galaxy is being invaded. Recent observations indicate that in
the next 100 million years, the
Sagittarius Dwarf galaxy
will move though the disk of our own
Milky Way Galaxy
yet again . The
Sagittarius Dwarf (Sgr), shown as the extended irregular
shape below the Galactic Center,
is the closest of 9 known small
dwarf spheroidal galaxies that orbit our Galaxy.
Don't worry, our Galaxy is not in danger,
but no such assurances are issued for the
Sagittarius Dwarf: the intense gravitational
tidal forces might pull it apart. Oddly, however,
Sgr's orbit indicates that is has been through
our Galaxy several times before, and survived!
One possibility is that Sgr contains a great deal of
low-density dark matter that hold it together
gravitationally during these collisions.
APOD: December 29, 1997 - The Milky Way in Infrared
Explanation:
At night, from a dark location, part of the clear sky looks
milky.
This unusual swath of dim light is generally visible during
any month and from any location.
Until the invention of the telescope,
nobody really knew what the "Milky Way" was.
About 300 years ago telescopes caused a startling revelation: the Milky Way was made of
stars.
Only 70 years ago,
more powerful telescopes
brought the further revelation that the
Milky Way is only one galaxy among many.
Now telescopes in space allow yet deeper understanding.
The
above picture was taken by the
COBE satellite
and shows the plane of our Galaxy in infrared light. The thin disk of our home
spiral galaxy
is clearly apparent, with stars appearing white and
interstellar dust appearing red.
APOD: November 5, 1997 - The Milky Way's Gamma-Ray Halo
Explanation:
Our Milky Way galaxy appears to be surrounded by a halo of gamma rays.
Gamma rays are the most energetic form of
electromagnetic radiation, with
more than a hundred thousand times the energy of visible light,
but known gamma-ray sources
don't account for the diffuse distribution of this high-energy glow.
This surprising result
is based on data
from the EGRET instrument onboard
the Compton Gamma Ray Observatory.
In this false color
all-sky image centered on
the Milky Way, the
brown and green regions indicate brighter, known sources of gamma-rays.
The galactic center and plane clearly standout as do some
distant galaxies seen near the top and bottom of the picture.
The dim, blue regions above and
below the plane correspond to our Galaxy's unexpected gamma-ray halo.
What causes the halo?
Future gamma-ray telescopes
could solve this mystery.
However, the excitement has already inspired tantalizing
speculation about the solution including;
collisions of low energy photons with
high-energy cosmic rays,
high energy electrons accelerated by a previous burst of
Milky Way star formation,
and exotic interacting particles which make up
Dark Matter.
APOD: October 3, 1997 - Comet Halley and the Milky Way
Explanation:
Comet Halley was photographed superposed in front of the disk of our
Milky Way Galaxy in 1986 by the
Kuiper
Airborne Observatory. Comet Halley is the bright white streak near this photograph's center.
Comet Halley is the most
famous comet in history, and returns to the inner
Solar System every 76 years.
Stars visible in our
Milky Way Galaxy typically lie
millions of times farther in the distance and
orbit the
Galactic center every 250 million years.
Billions of
comets are thought to orbit our
Sun
but most do not get close enough for us to see.
Similarly, billions of stars orbit our Milky Way's center but do not get close enough for us to see.
APOD: May 17, 1997 - 7,000 Stars and the Milky Way
Explanation:
This panorama
view of the sky is really a drawing.
It was made in the 1940s under the supervision of astronomer Knut Lundmark at
the Lund Observatory
in Sweden. To create the picture, draftsmen used
a mathematical distortion to map
the entire sky onto an oval shaped image with
the plane of our Milky Way Galaxy
along the center and the north galactic
pole at the top. 7,000 individual stars are shown as white dots, size
indicating brightness. The "Milky Way" clouds, actually the combined
light of dim, unresolved stars in the
densely populated galactic plane, are
accurately painted on, interrupted by
dramatic dark dust lanes.
The overall effect is photographic in quality and represents the visible
sky. Can you identify any familiar landmarks or constellations?
For starters,
Orion
is at the right edge of the picture, just below the galactic plane
and the Large and
Small Magellanic Clouds are visible as
fuzzy patches in the lower right quadrant.
APOD: April 30, 1997 - Milky Way Molecule Map
Explanation:
Where are the Milky Way's gas clouds and where are they going?
Stars form in gas clouds,
and the motion of gas clouds tell us about the
size and rotation speed of our own
Milky Way Galaxy.
But gas clouds are hard to detect - they are
composed mostly of nearly invisible molecular
hydrogen and
helium.
Fortunately, at least small amounts of heavier gases co-exist, one of them being
carbon monoxide (CO),
which is relatively easy to detect at radio wavelengths.
Therefore, over the past decade, a
team of astronomers have
carefully
mapped out the molecular sky to unprecedented
clarity - to about four times previous resolution
and about eight times previous sensitivity. The resulting
map is shown above,
rescaled and in false color, with dark blue
being relatively low emission. The band of our
Milky Way Galaxy
spans the middle. The data have not only helped our understanding of the
Galaxy,
but highlight a few mysteries too. For example:
what
causes the rapid speed of the gas near the
Galactic Center?
APOD: March 15, 1997 - The Milky Way's Center
Explanation: Although the Earth is round, our Galaxy appears
truly flat. This was shown in dramatic fashion by the COsmic Background Explorer (COBE)
satellite which produced this premier view of the central region
of our own Milky Way Galaxy
in infrared light in1990. The Milky Way
is a typical spiral galaxy with a
central bulge and extended disk of stars. However, gas and dust
within the disk obscure visible wavelengths of light effectively
preventing clear observations of the center. Since infrared
wavelengths are less affected by the obscuring material, the Diffuse InfraRed Background Experiment (DIRBE)
on board COBE
was able to detected infrared light from stars surrounding the Galactic center
and produce this image. Of course, the edge on perspective represents
the view from the vicinity of our Sun,
a star located in the disk about 30,000 light years out from the
center. The DIRBE
module used equipment cooled by a tub of liquid helium to detect
the infrared light which, composed of wavelengths longer than red light,
is invisible to the human eye.
APOD: March 4, 1997 - Solar Wind And Milky Way
Explanation:
The Sun is bright,
so bright that it overwhelms the light
from other stars even for most satellite-borne telescopes.
But LASCO, a coronograph onboard the
space-based SOHO Observatory, uses
occulting disks to block the intense solar light and examine
the tenuous, hot gases millions of miles above the Sun's surface.
In this
LASCO image from
December 24, 1996,
an occulting disk (center) and mechanical
support (extending from the lower left) are visible along with
the billowing Solar Wind.
Appearing in the background are
faint stars and obscuring dust clouds toward
the center of our Milky Way Galaxy!
The field of view covers about 16 degrees, corresponding to
28 million miles at the distance of the Sun - just under half the diameter
of Mercury's orbit.
A prominent dark interstellar dust cloud cuts through
the Milky Way starfield
running approximately south (lower right) to north.
Blemishes on the image are camera streaks caused by charged particles.
APOD: December 12, 1996 - The Milky Way Through the Summer Triangle
Explanation: There are more than a few stars in our Galaxy.
The light from many of them combines to appear as a wisp of faint
light across the night sky - the Milky Way.
In the northern hemisphere, away from city lights
and during the summer months, part of the Milky Way
can be seen behind the Summer Triangle
of stars - Deneb,
Vega,
and Altair.
These are the brightest three stars in the above photograph,
listed from left to right, respectively. If you could collect
light in your eyes for 10 minutes at a time (instead of the usual
1/10th of a second), you might see something like the
above photograph.
Behind the Summer Triangle
lies some of the vast star fields
of our Milky Way Galaxy, containing
literally billions
of stars. The dark band across the middle that seems to divide
the stars is actually interstellar dust,
which absorbs more visible light than it emits and so appears
dark.
APOD: July 23, 1996 - Hale-Bopp, Jupiter, and the Milky Way
Explanation:
Shining brightly,
the mighty Jupiter rules this gorgeous
Kodacolor photo of
the Milky Way near Sagittarius.
Astronomer Bill Keel took the picture earlier this month (July 7)
while standing near the summit of
Hawaii's Mauna Kea
contemplating the sky in the direction of the
center of the Galaxy (right of picture center).
In addition to the gas giant planet, which
is well placed for evening viewing,
the image contains an impressive sampler of celestial goodies.
Many famous emission nebulae
are visible as reddish patches -
M16, the Eagle nebula,
is just above and right of center, with
the Horseshoe nebula, M17, just below it and farther to the right.
Also, look for the Lagoon Nebula, M8, as
the brightest red patch at the right of the picture with
the Trifid Nebula, M20,
just above it and to the left.
The milky glow of distant unresolved stars
in the plane of our Galaxy (thus the term Milky Way) runs through
the image cut by dark, absorbing, interstellar
dust clouds.
The much anticipated
comet Hale-Bopp is also clearly visible. Where's the
comet? Click on the picture to view the comet's location
flanked by superposed vertical lines.
The comet was discovered while
still beyond the orbit of Jupiter
a year ago today independently by
Alan Hale
and Thomas Bopp. Astronomers monitoring
Hale-Bopp's activity report that
having now brightened to almost 6th
magnitude
it is still on track for becoming
an extremely bright naked-eye comet in early 1997.
APOD: June 5, 1996 - Sagittarius and the Central Milky Way
Explanation:
What does the center of our
Milky Way Galaxy look like? No one knows! It
is not possible to see the Galactic center in light our eyes are sensitive
to because the thick
dust in the
plane of our Galaxy obscures it. If one
looks in the direction of our Galaxy's center - which is toward the
constellation of Sagittarius - many beautiful wonders become apparent,
though. The center of the Milky Way is behind the center of the photo.
Large dust lanes and star clouds dominate the picture.
As many as 30
Messier Objects
are
visible, including all types of nebula and star
clusters. Two notable nebula include the
Lagoon Nebula (M8), a small red
patch just above center, and slightly above this is the red and blue
Trifid
Nebula (M20). The lines through picture were caused by airplanes, and the
dark objects in the foreground are trees.
APOD: May 15, 1996 - The Milky Way Near the Northern Cross
Explanation:
This beautiful image of the sky near the bright star
Deneb
(just above center) reveals the stars, nebulae, and dark clouds
along the plane of our Milky Way Galaxy as seen from the northern
hemisphere (near Columbia Missouri, USA).
Just below Deneb lies the suggestively shaped North America emission nebula.
Deneb is
the brightest star in the constellation
Cygnus,
located in the tail of this
celestial swan.
Cygnus
contains the asterism known as the Northern Cross and
marks one side of the "Great Rift" in the Milky Way, a series of dark
obscuring dust clouds which stretches on through the constellation
Sagittarius.
Deneb defines the top of the Northern
Cross while the body of the cross extends past the
upper right corner of the picture.
Cygnus also harbors the most famous
candidate for a black hole in our galaxy,
Cygnus X-1.
APOD: February 13, 1996 - 7,000 Stars And The Milky Way
Explanation:
This panorama
view of the sky is really a drawing.
It was made in the 1940s under the supervision of astronomer Knut Lundmark at
the Lund Observatory
in Sweden. To create the picture, draftsmen used
a mathematical distortion to map
the entire sky onto an oval shaped image with
the plane of our Milky Way Galaxy
along the center and the north galactic
pole at the top. 7,000 individual stars are shown as white dots, size
indicating brightness. The "Milky Way" clouds, actually the combined
light of dim, unresolved stars in the densely populated galactic plane, are
accurately painted on, interrupted by
dramatic dark dust lanes.
The overall effect is photographic in quality and represents the visible
sky. Can you identify any familiar landmarks or constellations?
For starters,
Orion
is at the right edge of the picture, just below the galactic plane
and the Large and
Small Magellanic Clouds are visible as
fuzzy patches in the lower right quadrant.
APOD: September 8, 1995 - The Milky Way's Center
Explanation:
NASA's
COBE satellite scanned the heavens at infrared wavelengths in
1990 and produced this premier view of the central region of our own Milky Way
Galaxy. The Milky Way is a typical spiral
galaxy with a central bulge and extended disk of stars. However, gas
and dust
within the disk obscure visible wavelengths of light effectively
preventing clear observations of the center. Since infrared
wavelengths, are less affected by the obscuring material, the
Diffuse InfraRed Background Experiment (DIRBE)
on board COBE was able to
detected infrared light from stars surrounding the galactic center and
produce this image.
Of course, the edge on perspective represents
the view from the vicinity of our Sun,
a star located in the disk about 30,000 light years out from the center.
The DIRBE experiment used equipment cooled by a tub
of liquid helium to detect the infrared light which, composed of wavelengths
longer than red light, is invisible to the human eye.