How the ExoMars mission could sniff out life on Mars--and what to do next

"It (could be) life Jim, but (perhaps) not as we know it." This is not just a sci-fi catchphrase, but also something some planetary scientists have uttered in response to the discovery of methane in Mars' atmosphere. That's right - scientists believe that some kind of past or present microbial lifeform on Mars could have produced the methane. While it is far from the only possible explanation, it is actually so plausible that a special mission is being sent there to find out.