Posted: Wed, Jul 25, 2001, 10:54 PM ET (0254 GMT)
New images of Mars published this week show evidence of what planetary scientists believe to be recent climate change on the Red Planet as well as water ice. The Mars Global Surveyor images, published in Thursday's issue of the journal Nature, show an unusual terrain of pits and hummocks in several areas of the planet. Scientists believe the terrain formed within the last 100,000 years as ice, mixed in the soil in these regions, evaporated. The discovery is significant because it implies that water ice existed at relatively low latitudes -- the terrain lies between 30 and 60 degrees latitude -- in the recent past. It is possible that some water ice may exist below the surface in those regions, in terrain that is not pitted. The presence of ice this close to the equator suggests that the planet has gone through some amount of climate change in the recent geologic past that allowed ice to form closer to the equator before retreating the poles, analogous to ice ages on Earth.

Related Links:

•  Brown University press release
•  AP article