The Curiosity rover sent to Mars has finally answered a key question about Mars: the red planet in the past had some ingredients needed to support primitive life.
Several billion years ago, Mars may have been a pleasant place for tiny organizms, as it had enough water and minerals that could have served as food, NASA scientists revealed Tuesday at a news conference on the latest findings from their rover. But they have yet to find signs that actual microbes did live in that oasis.
“We have found a habitable environment that is so benign and supportive of life that probably if this water was around and you had been on the planet, you would have been able to drink it,” said chief scientist John Grotzinger of the California Institute of Technology.
The rover made a dramatic “seven-minutes-of-terror” landing last summer near Mars’s equator. A key task was to find out whether ancient Mars ever had favorable conditions for microscopic organisms.
“A fundamental question for this mission is whether Mars could have supported a habitable environment,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “From what we know now, the answer is yes.”
The Curiosity rover is not equipped to detect microbes, living or extinct, but it can use its onboard tools and laboratories to examine Martian rocks to determine the kind of environment they might have lived in, explains Time.
The analysis unveiled signs that the rock contained clay minerals that formed in a watery environment. It also had certain ammounts of sulfur, nitrogen, hydrogen, oxygen, phosphorus and simple carbon — chemical ingredients essential for life.
Unlike some places on the red planet, scientists explained that the ancient water at the rock appeared to be neutral and not too salty. Curiosity previously found a hint of the site’s watery past — an old streambed that the six-wheel rover crossed to get to the flat bedrock.
Scientists were quite surprised to find a mixture of oxidized, less-oxidized, and even non-oxidized chemicals, providing an energy gradient of the sort many microbes on Earth exploit to live. This partial oxidation was first hinted at when the drill cuttings were revealed to be gray rather than red.
“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,” said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA’s Goddard Space Flight Center in Greenbelt, Md.
An additional drilled sample is believed to help scientists confirm these results for several of the trace gases analyzed by the SAM instrument.
“We have characterized a very ancient, but strangely new ‘gray Mars’ where conditions once were favorable for life,” said John Grotzinger, Mars Science Laboratory project scientist at the California Institute of Technology in Pasadena, Calif.
“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.”