Martian valleys and craters

The relatively flat expanse of the Martian valley known as Mawrth Vallis is among four places NASA may land its next big thing: the roving Mars Science Laboratory.

Slated for launch in 2011, the SUV-size rover will carry a fleet of advanced equipment for studying the red planet--enabling, among other things, tests for whether Mars ever gave rise to life and whether the planet could ever be suitable for human habitation. Mawrth Vallis interests researchers because of its different clay layers, which might offer new clues to Mars's watery past.



The youngest crater ever found by a Mars rover, Resolution clocks in at a mere hundred thousand years old. By contrast, some of the craters seen so far by the Mars rover Opportunity seem to date back more than three billion years.

Rocks scattered by the impact that formed Resolution are still fresh and sharp--clues to its status as a relative newborn. Over time these rocks will be eroded by Martian winds, and the crater bowl will fill with sand. Comparing this whippersnapper to older craters can therefore help researchers figure out how fast wind action changes the red planet's surface.