Mars Science Lab Project Manager and professor of geology at California Institute of Technology John Grotzinger presented new evidence of ancient habitability on Mars, based on the findings from the Curiosity rover, in a lecture on Thursday evening. On Tuesday, the Jet Propulsion Laboratory in Pasadena, Calif. announced that Curiosity’s current location in Gale Crater very likely could have hosted microbial life.
Grotzinger explained that this particular location was chosen because it promised to have relevance to multiple interests in the search for habitability on Mars. The rover’s eventual destination for the rover is Mount Sharp.
Researchers receiving Curiosity’s findings back on Earth were first struck by the rock’s surprising color — on the famous Red Planet, the rock in Gale Crater was gray.
“Red Mars turned gray at Gale Crater,” Grotzinger said.
The rock found in Gale Crater has been notable to scientists because it suggests a long history of interaction with neutral pH water. This water, which would likely have had a low salinity concentration, would have been far more inviting to microbial life than any other location.
Researchers found that the magnetite found in the rock was not fully oxidized. The discovery of both oxidized and reduced substances in these samples suggests that microorganisms that subsist simply on the chemical energy potential present within a rock could have lived within the Gale Crater rock.
Back on Earth, scientists like Princeton’s own Tullis C. Onstott have touted the importance and vitality of prokaryotes that live in extreme habitats like these in recent years. These so-called “extremophiles” were probably the first organisms on Earth, Grotzinger explained.
“This is the most complex spacecraft ever to be sent to the surface of another planet,” Grotzinger said as he explained an image of Curiosity’s insides. Curiosity is equipped with tools with names like CheMin, Curiosity’s X-ray diffraction instrument, and Dust Removal Tool.
One of the challenges of the Mars mission has been the need for vigilant communication with the rover, Grotzinger explained. Furthermore, the scientists must take meticulous precautions in every action. Not only must every movement be simulated on Earth before it can happen on Mars, but every sample must be taken several times in order to prevent contamination.
This time commitment can become a problem when Mars begins its transit behind the Sun. For that period of about a month, the Earth will not be able to communicate by radio signals with Curiosity.
Grotzinger expressed his anticipation for the coming Mars Sample Return Mission scheduled for launch in 2020.