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.

January 12, 1999
See Explanation.  Clicking on the picture will download 
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The Wind on Mars
Credit: MOC Team, MGS, NASA

Explanation: Wind erosion has been discovered on Mars. Pictures of regions surrounding the north polar cap show sand dunes covered in frost. In places, however, this frost has been eroded to uncover the dark sand underneath. Since this frost can only be as old as the Martian winter is long, this erosion must have taken place within the past Martian year. Once established, it is easy to visualize that much of the appearance of the above region has been sculpted by wind blown dust. Because the Martian atmosphere is so thin, a person standing on Mars would not get blown over by these Martian winds.

Tomorrow's picture: Star Cloud

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.