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 June 4
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A Martian Metamorphosis
Credit: Malin Space Science Systems, MOC, MGS, JPL, NASA

Explanation: Is it an Escher, or Mars? Three different types of surfaces visible in the North Polar Cap of Mars morph into each other in a way perhaps reminiscent of the works of M. C. Escher. On the far left dark sand covers the ground, while the centre shows a transition to a dune field. On the far right a transition is made to a much lighter surface, likely containing a larger amount of ice. Shadows indicate that lighter material holds the higher ground, with some steep cliffs on the divide. Dune shapes indicate that wind typically blows toward the upper left. Mars Global Surveyor, one of two robot spacecraft currently orbiting Mars, took the above image in early 2001. Recent images from the other orbiter, Mars Odyssey, have bolstered the hypothesis that a significant amount of water-ice lies beneath the surface near the Martian South Pole.

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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.