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.

2002 February 19
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Water-Ice Imaged in Martian Polar Cap

Explanation: Does water exist today on Mars? Yes, although the only place on Mars known to have water is the North Polar Cap, and that water is frozen. Views of this potentially life-enabling water-ice are usually obscured -- in the winter by darkness and in the summer by clouds. Last April, however, the orbiting Mars Global Surveyor spacecraft was able to get a good glimpse of the water-bearing cap just before Martian spring. Low, dark layers in the above image are thought to contain a large amount of sand, while high, light layers likely contain higher amounts of water-ice. The image spans an area about 5 kilometers across.

Tomorrow's picture: Spin Faster

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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.