Signs Of Life On Mars? Not Exactly

The director of NASA's Jet Propulsion Laboratory said last week that preliminary data showed the possibility that the agency's Mars Science Laboratory – the six-wheeled rover that landed on Mars in August — had found signs of carbon-containing molecules.

According to a JPL news release, however, there will be no major announcements Monday, when scientists take part in a news conference at the annual meeting of American Geophysical Union. The science team is continuing to try and verify what the rover has found.

So why are the scientists being so careful with their findings and why are these carbon-containing molecules of such great interest?

"It's a substance that's consistent with biological materials," says John Grotzinger of the California Institute of Technology, the chief scientist on the rover team.

Now don't start thinking that because some carbon-containing compounds are associated with biological materials he's talking about life on Mars. Grotzinger says it doesn't have to be biological materials; there are plenty of carbon-containing compounds that have nothing to do with life.

But finding certain of these carbon molecules would be exciting because of what it might say about the Martian environment where the rover is sitting at the bottom of Gale crater.

If one kind of carbon can survive there, it might just be a place where carbon molecules that are related to living organisms could also survive as a kind of chemical fossil.

"There wouldn't be a field of paleontology unless you found the hot spots where things get preserved," Grotzinger says.

Grotzinger says the rover is looking for those hot spots; places where carbon-containing chemicals consistent with life might have been preserved and still exist.

"[But] even if they have nothing to do with life, at least it tells us that this is the kind of environment that might have been favorable for preservation of something that could be a biological material," he says.

Even the possibility of finding carbon compounds on Mars causes excitement, which certainly is not true for every planet. In the current issue of the journal Science, researchers reported they were virtually certain that had found large deposits of organic compounds on the planet Mercury, and that wasn't front page news.

"I can tell you anytime when you find anything with Mars, it's a frenzy," says Maria Zuber of the Massachusetts Institute of Technology, one of the Mercury researchers who also works on Mars.