Scientists this week began assessing what may be the most important part of an upcoming mission to look for life on Mars: location, location, location.
Europe's ExoMars rover, slated for launch in 2018, will be the most focused and ambitious attempt to find evidence of past or present life on Mars since NASA's Viking expeditions four decades ago.
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ExoMars' planners aren't starting from scratch, however. Recent findings from NASA's Mars Science Laboratory Curiosity mission, for example, indicate that ExoMars may not have drill down very deep -- or perhaps not at all -- to collect viable samples for analysis.
ExoMars will carry a drill capable of burrowing up to 6.6 feet (2 meters) into the planet's surface. Scientists figure that at that depth, organic materials -- if they exist -- would be shielded from the onslaught of damaging radiation that constantly pummels the planet.
"One of the things that Curiosity has been able to do is understand that not all surfaces on Mars are created equal and have equal ages," California Institute of Technology geologist John Grotzinger, who leads the rover's science team, told Discovery News.
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Last year, researchers discovered that Mars' winds sometimes do the digging for them, exposing relatively fresh rocks at the base of scarps.
"One result from MSL that may be useful is that the depth (to collect samples) maybe less than 2 meters," ExoMars project manager Vincenzo Giorgio told Discovery News. "We can definitely accommodate that."
"If it turns out that drilling is complicated and inefficient, you can save that capability for when you need it the most," Grotzinger added.
Unlike ExoMars, Curiosity was not designed to look for life directly. Instead, it is assessing if a region of Mars, known as Gale Crater, has or ever had the necessary ingredients and environments to support life.