http://www.cnn.com/2001/TECH/space/07/25/martian.permafrost.ap/index.html

Mars orbiter finds traces of past ice age
Associated Press
July 25, 2001

(AP) -- Recent NASA images from Mars indicate that a significant amount of water may be stored near the surface of the red planet in a sort of martian permafrost.

Pictures taken by the Mars Global Surveyor spacecraft, which began mapping the planet in 1999, show regions of smoothly undulating hills interspersed with bumpier ground.

In Thursday's issue of the journal Nature, geologists interpret the smooth hills as mounds of dust frozen solid by ice. The bumpy areas between them appear to be places where the ice has disappeared and the powdery red soil has blown away.

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