NASA's Curiosity rover has gulped in Martian air but failed to find methane – a gas linked to living things. But it has turned up signs that Mars may have lost much of its original atmosphere.
Since landing on the Red Planet's surface Aug. 5, the Mars Science Laboratory rover has zapped rocks with its laser, dug its toes into sand dunes at its current location, Rocknest, and even scooped up Martian soil for a little taste in its laboratory belly. Now it has breathed in the Martian atmosphere, looking for clues as to the composition of Mars' atmosphere.
Mars' atmosphere is very thin – a mere 100th the density of the Earth's – and too thin to easily support life. But planetary scientists think the atmosphere was once much thicker – and they want to find out why so much of it disappeared.
For this exercise, the rover used the Sample Analysis at Mars suite. Though it's one of the two instruments in the payload that is famous for being able to ingest dirt, it can also analyze gasses.
"SAM can take many different types of measurements," said Laurie Leshin of the Rensselaer Polytechnic Institute, a SAM co-investigator. "I think of it like a Swiss Army knife: It's a beautifully integrated set of tools that can do many jobs … and of course it's right there in Curiosity's pocket."