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.
2023 December 23
Explanation: Colours of a serene evening sky are captured in this 8 minute exposure, made near this December's solstice from New Zealand, southern hemisphere, planet Earth. Looking south, star trails form the short concentric arcs around the rotating planet's south celestial pole positioned just off the top of the frame. At top and left of center are trails of the Southern Cross stars and a dark smudge from the Milky Way's Coalsack Nebula. Alpha and Beta Centauri make the brighter yellow and blue tinted trails, reflected below in the waters of Hoopers Inlet in the Pacific coast of the South Island's Otago Peninsula. On that short December summer night, aurora australis also gave luminous, green and reddish hues to the sky above the hills. Aurora shine as atoms and molecules in the upper atmosphere are excited by collisions with energetic particles. An upper atmospheric glow distinct from the aurora, a pale greenish airglow caused by a cascade of chemical reactions excited by sunlight, can be traced in diagonal bands at top left.
Authors & editors:
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.