Mars rover Curiosity soil analysis: why no news still isn't bad news

Mars rover Curiosity soil analysis: why no news still isn't bad news - CSMonitor.com

Curiosity's SAM detected some simple hydrocarbons made up of chlorine and methane. Does that mean Martian-based organics are in the bag? The team suspects not, although it is conducting a thorough analysis. Surface soils are exposed to a range of radiation and chemicals in the atmosphere that tend to dismantle organic compounds.

The researchers say they suspect that the chlorine came from perchlorates in the soil, perhaps calcium perchlorate, Dr. Mahaffy says. Perchlorates are chlorine-based salts. The Phoenix Mars lander found perchlorates in abundance at its polar landing site in 2008.

The carbon in the methane is another story, however. It could represent residual contamination from Earth, despite extensive efforts to scrub the rovers before launch. Or the carbon could have come from the soil. But carbon in soils could be organic as well as inorganic. Indeed, Mahaffy holds out the possibility that the simples forms of chloromethane SAM detected could have formed during the analysis process, with carbon dioxide freed from the soil samples as they were heated serving as the source of the carbon. If the carbon is organic, researchers still have to figure out if the carbon is indigenous to Mars, or hitched a ride to the surface on micrometeoroids.

Given the various ways organic compounds can be destroyed on the Martian surface, "it's really going to be an exciting hunt ... over the course of this mission to find early environments that might be kind of protected from this harsh surface environment and really see what we can add to the organics story," Mahaffy says.

Mars just seems to have that effect on people.

The next news conference about the NASA Mars rover Curiosity will be held at 9 a.m. PST(12 p.m. EST) Monday, Dec. 3, in San Francisco at the Fall Meeting of the American Geophysical Union (AGU). 

Rumors and speculation that there are major new findings from the mission at this early stage are incorrect. The news conference will be an update about first use of the rover's full array of analytic instruments to investigate a drift of sandy soil. One class of substances Curiosity is checking for is organic compounds -- carbon-containing chemicals that can be ingredients for life. At this point in the mission, the instruments on the rover have not detected any definitive evidence of Martian organics. - JPL NEWS RELEASE 2012-377b

As noted in an earlier posting here, the director of NASA's Jet Propulsion Laboratory said last week that preliminary data showed the possibility that the agency's Mars Science Laboratory  –  better knowed as Curiosity — had found signs of carbon-containing molecules as "one for the history books."

According to the above  JPL news release, there will be no major announcements Monday in San Francisco at the  annual meeting of American Geophysical Union. 

The science team is continuing to try and verify what the rover has found. "Carbon compounds are  a substance that's consistent with biological materials," says John Grotzinger of the California Institute of Technology, the chief scientist on the rover team, but Grotzinger says it doesn't have to be biological materials; there are plenty of carbon-containing compounds that have nothing to do with life.

However, finding 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. The NASA Mars rover Curiosity  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.