Scientists at NASA suggest that the Mars Science Laboratory rover, Curiosity, which is expected to land on Mars this August, has a higher than previously expected chance of detecting organic molecules on the Martian surface. The discovery of complex organic molecules would be strong evidence for the possibility of past Martian life.
New research by NASA scientist Alexander Pavlov and his colleagues suggests that it might be possible to find these organic molecules only a few inches below the planet’s surface. Previous Martian landers have only collected and analysed the top layer of loose soil, which Pavlov believes would be far too irradiated to still contain complex carbon chains.
Complex carbon structures are very vulnerable to cosmic radiation and quickly decay on the weakly-protected Martian surface. Pavlov reports that the top two centimetres of Martian soil would have almost no chance of having organic molecules due to the radiation, but proposes that at a depth of five centimetres, some of the simpler organic molecules, like formaldehyde, could survive the radiation.
But even if the Mars rover discovers complex carbon chains, further testing would be necessary before any claims of Martian life could be made; complex organic molecules on the Martian surface could also be the result of volcanic eruptions and meteorites.
The optimal location to find organic molecules free from radiation would be over 1.5 metres below the surface, but drilling that deep is currently too expensive to accomplish. Instead, Curiosity will attempt to mine soil samples from craters no more than 10 million years old. Drilling in these craters will allow the rover to reach new depths of soil that have not been exposed to cosmic radiation for very long.
Curiosity is scheduled to land in the Gale crater on August 6, 2012, the same location where the previous rover, Spirit, landed in 2004.
Source: Science Daily