Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 May 3
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Moonrise Through Mauna Kea's Shadow
Image Credit & Copyright: Michael Connelley (U. Hawaii)

Explanation: How can the Moon rise through a mountain? It cannot -- what was photographed here is a moonrise through the shadow of a large volcano. The volcano is Mauna Kea, Hawai'i, USA, a frequent spot for spectacular photographs since it is arguably the premier observing location on planet Earth. The Sun has just set in the opposite direction, behind the camera. Additionally, the Moon has just passed full phase -- were it precisely at full phase it would rise, possibly eclipsed, at the very peak of the shadow. The Moon is actually rising in the triangular shadow cone of the volcano, a corridor of darkness that tapers off in the distance like converging train tracks. The Moon is too large and too far away to be affected by the shadow of the volcano. Refraction of moonlight through the Earth's atmosphere makes the Moon appear slightly oval. Cinder cones from old volcanic eruptions are visible in the foreground.

Tomorrow's picture: aurora moon

< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.