NASA's Rover's Helps Fingerprint Martian Minerals

'Bite mark' in Martian soil made by Curiosity rover
Image credit: NASA/JPL-Caltech/MSSS

Mars rover Curiosity has completed initial experiments showing the mineralogy of Martian soil is similar to weathered basaltic soils of volcanic origin in Hawaii.  The minerals were identified in the first sample of Martian soil ingested recently by the rover. Curiosity used its Chemistry and Mineralogy instrument (CheMin) to obtain the results, which are filling gaps and adding confidence to earlier estimates of the mineralogical makeup of the dust and fine soil widespread on the Red Planet. 

The identification of minerals in rocks and soil is crucial for the mission's goal to assess past environmental conditions. Each mineral records the conditions under which it formed. The chemical composition of a rock provides only ambiguous mineralogical information, as in the textbook example of the minerals diamond and graphite, which have the same chemical composition, but strikingly different structures and properties. 

David Bish, co-investigator with Indiana University in Bloomington, said, "Much of Mars is covered with dust, and we had an incomplete understanding of its mineralogy. So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment. The ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water." 

During the two-year prime mission of the Mars Science Laboratory Project, researchers are using Curiosity's 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life.