src: Curiosity Cam
press release MSL image archive
Yesterday's NASA press conference discussed some of the results from the analysis of the Gale Crater drilled rock powder. The x-ray diffraction analysis of the rock interior indicated the presence of clay minerals called smectites which are formed by the action of water in a nearly neutral pH environment. The SAM quadrapole mass spectrometer detected water, carbon dioxide, sulphur dioxide, oxygen and hydrogen sulphide. The deuterium-hydrogen ratio was the lowest detected so far. These results indicate the presence of an aqueous habitable environment in Mars' past. The focus of study now shifts from the search for water to a search for a habitable environment. The term habitable was qualified to mean an "environment a microbe could have lived in." Even though an environment may lack organics it may be habitable for microbial life if there are organic minerals that it can feed on and a source of carbon that it can use to form organic molecules. The presence of a "carbon signal" is dependent on three components. There has to be a mechanism for concentrating carbon. The environment has to be such that it will preserve organic material. On Earth heat can break down organic material over long periods of time. Finally, the radiation environment has to be favorable.