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APOD

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.

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

Orion and Aurora over Iceland

Explanation: If you see a sky like this -- photograph it. A month ago in Iceland , an adventurous photographer chanced across a sky full of aurora and did just that. In the foreground lies the stratovolcano rfajkull . In the background, among other sky delights, lies the constellation of Orion , visible to the aurora's left. Auroras are sparked by energetic particles from the Sun impacting the magnetic environment around the Earth. Resultant energetic particles such as electrons and protons rain down near the Earth's poles and impact the air. The impacted air molecules obtain excited electrons, and when electrons in oxygen molecules fall back to their ground state, they emit green light. Auroras are known to have many shapes and colors .

Click Hyperspace: Random APOD Generator

Date March 24, 2014
Credit Image Credit & Copyright: orvarur rnason
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.