NASA’s Mars Curiosity rover, a resident of the red planet’s Gale Crater since early August, this week confirmed what many planetary scientists have long believed — Mars was once warm and wet enough to support microbial life.
The announcement Tuesday was based on the result of material drilled from a rock in Gale Crater with a Curiosity drill on Feb. 8.
The excavated gray material included clay minerals which form in a neutral form of water on the Earth as well as sulfur, nitrogen, hydrogen, oxygen, among other chemical elements common to terrestrial microbial activity.
“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. “From what we know now, the answer is yes.”
Launched in late 2011, Curiosity carried out a dramatic landing in Gale Crater on Aug. 6, 2012, as the centerpiece of a $2.5 billion, two-year mission to determine whether the contemporary, cold, dry almost airless Martian realm once had conditions favorable for life.
John Grotzinger, the Curiosity’s chief mission scientist, said findings so far point to habitable environs more than three billion years ago, which begins to corresponds to when life emerged on the Earth.
NASA’s smaller Opportunity rover made a similar discovery in 2004, several months after landing in a different region of Mars, Meridiani Planum. However, the soil chemistry assessed by Opportunity pointed to a very acidic water environment, one that would require any microbes to be classified as “extremophiles” by Earthly standards.
With the discovery of clay minerals, Curiosity’s latest findings greatly expand the possibilities for microbial life on early Mars.
“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,” Grotzinger told a NASA news briefing.
Curiosity’s work is far from over.
Under the supervision of NASA scientists, Curiosity remains in search of “organics,” the more complex carbon-based chemistry that would suggest biological activity, something much more significant than environmental conditions suitable for life.
Also, Mount Sharp rises 18,000 feet from the center of Gale Crater. Curiosity will “drive up” the peak to study soil and rock that was deposited in the region in more recent times. The findings could reveal when conditions on Mars turned less favorable for biological activity.
Meanwhile on the Earth this week, the Smithsonian Institution announced that the 2013 National Air and Space Museum Trophy for current achievement will be awarded to Curiosity’s Entry, Descent, and Landing Team from NASA’s Jet Propulsion Laboratory. Their work produced the aero shell, parachutes and the giant sky crane that delivered the one ton rover safely to the ground.
The award will be presented in Washington on April 24.