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.

2014 January 8
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Sunspot at Sunset
Image Credit & Copyright: Jürg Alean

Explanation: Sunsets may be the most watched celestial event, but lately sunsets have even offered something extra. A sunspot so large it was visible to the naked eye is captured in Swiss skies in this sunset scene from January 5, crossing left to right near the centre of a solar disk dimmed and distorted by Earth's dense atomosphere. Detailed views reveal a large solar active region composed of sunspots, some larger than planet Earth itself. Catalogued as active region AR 1944, on January 7 it produced a substantial solar flare and a coronal mass ejection (CME) forecast to reach Earth. The CME could trigger geomagnetic storms and aurora on January 9.

Tomorrow's picture: tadpoles in a cosmic pond


< | Archive | 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.