Curiosity rover finds ancient Mars was suitable for life

The analysis results of the first-ever rock drilling on Mars, by the Curiosity rover, were announced today by NASA at a press briefing in Washington. The new findings indicate that ancient Mars, at least in this area, was habitable and could have supported some form of life.

Mission scientists had already determined that the area around Curiosity’s landing site was once “soaking wet” with water, and that a stream or small river once flowed nearby. Gale crater itself may have been a shallow lake.

Now, the new chemical analysis of material from deeper inside a slab of becrock, thought to be a mudstone, shows that the water had a neutral pH rather than being highly salty or acidic like the water in some other areas as documented by previous rovers. Also, all of the chemical ingredients necessary for life (as we know it anyway) were present as well. The SAM and CheMin labs on Curiosity identified water, carbon dioxide, sulfur dioxide, hydrogen sulfide, nitrogen, oxygen, phosphorus and carbon in the rock sample. The material from inside the rock is distinctly grey, instead of the usual reddish-brown like the dust-covered surface.

At least 20% of the rock sample is composed of smectite clay minerals, which result from the interaction of fresh water with other minerals. As noted during the press conference, the closest analogy on Earth would indeed be a lakebed. The drill site, called John Klein, is near the end of an alluvial fan where water once flowed from the stream down into the crater and spread out (or emptied into the lake), leaving the deposits behind after the water later disappeared.

The carbon found so far is in the form of chloromethane and dichloromethane, also seen previously at the Rocknest location. Further testing is still necessary to determine if it is indigenous to Mars, was produced by the reaction between Martian carbon and chlorine when the sample was heated in the SAM oven or was leftover terrestrial carbon on the drill itself.

While this doesn’t prove that life existed, it does show that the conditions were more than adequate and that energy sources needed to sustain microbes were present. According to Paul Mahaffy, principal investigator of the SAM slaboratory instruments, “The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulfates and sulfides that indicate a possible chemical energy source for micro-organisms.”

As Michael Meyer, lead scientist for NASA’s Mars Exploration Program, stated, “A fundamental question for this mission is whether Mars could have supported a habitable environment. From what we know now, the answer is yes.”

“We have characterized a very ancient, but strangely new ‘gray Mars’ where conditions once were favorable for life,” said John Grotzinger, Curiosity project scientist at the California Institute of Technology. He adds, “Curiosity is on a mission of discovery and exploration, and as a team we feel there are many more exciting discoveries ahead of us in the months and years to come.”

This article was first published on Examiner.com.