Eeny, Meeny, Miny, Mars
NASA's next Mars rover will land either beside the site of a former river delta or beside a mountain of stacked layers. These enticing locations are the two finalists as the Mars Science Laboratory landing sites: Eberswalde crater and Gale crater.
Selection of one of those sites is anticipated this month. The mission's spacecraft, including the rover named Curiosity, is in preparation for launch in the period Nov. 25 to Dec. 18, 2011.
As a clay-bearing site where a river once flowed into a lake, Eberswalde crater offers a chance to use knowledge that oil industry geologists have accumulated about where in a delta to look for any concentrations of carbon chemistry, a crucial ingredient for life.
At the other option, the mountain inside Gale crater could provide a route for the rover to study a transition from environments that produced clay deposits near the mountain's base to later environments that produced sulfate deposits partway up the slope.
The spacecraft will arrive at Mars in August 2012. Researchers will use the rover's 10 science instruments during the following two years to investigate whether the landing area has ever offered environmental conditions favorable for microbial life.