At a press conference Tuesday, scientists revealed NASA's Curiosity rover has uncovered signs that ancient Mars had the essential elements necessary for supporting life.
A rock sample analyzed by Curiosity in February contained sulfur, nitrogen, hydrogen, oxygen, phosphorous and carbon, critical building blocks for a living organism. An ancient streambed, analyzed in September, also contained minerals likely to have formed in the presence of "relatively fresh water," according to a written statement from NASA.
"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., in the statement. "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."
"A fundamental question for this mission is whether Mars could have supported a habitable environment," added Michael Meyer, lead scientist for NASA's Mars Exploration Program in Washington. "From what we know now, the answer is yes."
@MarsCuriosity, a Twitter account associated with the rover, gave itself a well-deserved pat on the back Tuesday:
The finding comes via Curiosity's drill, which uncovered a sample of gray soil quite different from the typical heavily oxidized ground that gives the 'Red Planet' its famous color, according to the Los Angeles Times.
The sample was taken in Mars' "Yellowknife Bay" area, then analyzed aboard the rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments to reveal the rock's specific chemical composition.
Curiosity first came across organic matter on Mars in December 2012.
A highly-anticipated announcement said to be "one for the history books" revealed organic molecules known as chloromethanes; at the time, scientists were concerned the carbon-hydrogen-chlorine compounds may have been inadvertently carried to Mars from Earth.
This latest announcement comes less than two weeks after a malfunction in Curiosity's main computer corrupted data and forced the rover into a "safe mode" of minimal activity. A backup computer, installed for precisely this scenario, has been activated and used to repair the main computer.
This set of images compares rocks seen by NASA's Opportunity rover (left) and Curiosity rover (right) at two different parts of Mars. The rocks observed by Opportunity were determined to have been uninhabitable due to high acidity, but the rocks observed by Curiosity were likely submerged in a more neutral liquid environment, raising the possibility that they could have once hosted life.
This image from Curiosity shows the first sample of Mars rock extracted by the rover's drill.
X-ray diffraction patterns of samples from two different areas on Mars' surface. On the left, a windswept, rocky environment that was likely uninhabitable; on the right, a lake-bed environment with likely neutral pH that may have been capable of supporting life.
A modern, Earth analog to the area NASA's Curiosity rover is currently exploring. Left, clay-bearing lake sediments exposed in a pit in southern Australia. Right, a core sample from the lakebed.
Left, a rock abraded by instruments on the Opportunity rover, showing reddish brown soil indicative of hematite, a substance not especially conducive to hosting life. Right, a hole drilled by Curiosity, showing the greyish, iron-rich rock underneath, which may be more compatible with habitability.
This map depicts the area in Gale Crater where the Curiosity touched down. The "John Klein Rock" is where Curiosity drilled its first soil sample.
A chemical analysis of a sample taken by Curiosity indicates the presence of water, carbon dioxide, oxygen, sulfur dioxide, and hydrogen sulfide released on heating.
The "John Klein" sample reveals the presence of simple carbon-containing compounds chloro- and dichloromethane in Mars' soil. These detections indicate that the analysis instruments are functioning properly and can continue searching for organic compounds.