CURIOSITY AND ANCIENT LIFE ON MARS
The red color of Mars points at least to a past with plenty of oxygen (Updated 4/14/2014)
March 12, 2013
PASADENA, Calif. -- An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes.
Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon -- some of the key chemical ingredients for life -- in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month. Note: Those elements in bold print are needed for DNA.
"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."
Clues to this habitable environment come from data returned by the rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine-grained mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty.
The patch of bedrock where Curiosity drilled for its first sample lies in an ancient network of stream channels descending from the rim of Gale Crater. The bedrock also is fine-grained mudstone and shows evidence of multiple periods of wet conditions, including nodules and veins.
Curiosity's drill collected the sample at a site just a few hundred yards away from where the rover earlier found an ancient streambed in September 2012.
"Clay minerals make up at least 20 percent of the composition of this sample," said David Blake, principal investigator for the CheMin instrument at NASA's Ames Research Center in Moffett Field, Calif.
These clay minerals are a product of the reaction of relatively fresh water with igneous minerals, such as olivine, also present in the sediment. The reaction could have taken place within the sedimentary deposit, during transport of the sediment, or in the source region of the sediment. The presence of calcium sulfate along with the clay suggests the soil is neutral or mildly alkaline.
Scientists were 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 will be used to help 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."
Scientists plan to work with Curiosity in the "Yellowknife Bay" area for many more weeks before beginning a long drive to Gale Crater's central mound, Mount Sharp. Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions.
NASA's Mars Science Laboratory Project has been using Curiosity to investigate whether an area within Mars' Gale Crater ever has offered an environment favorable for microbial life. Curiosity, carrying 10 science instruments, landed seven months ago to begin its two-year prime mission. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the project for NASA's Science Mission Directorate in Washington.
For more about the mission, visit: http://www.jpl.nasa.gov/msl , http://mars.jpl.nasa.gov/msl/ and http://www.nasa.gov/msl . You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity
DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
· General Response by the Roffman Team: There are two processes at work with respect to the Mars Science Laboratory Rover Curiosity. The prime aspect of this mission is geology, and we do not challenge the results in this area. In fact, we applaud them, as we do the magnificent landing itself back on August 6, 2012. The secondary aspect that relates to meteorology, however, we feel is an utter disaster where the only issue worth investigating is one of incompetence vs. deliberate disinformation. For a quick synopsis of this charge, see our PowerPoint entitled MARS CORRECT: Critique of all NASA Mars Weather Data, With Emphasis on Pressures. For a more in depth analysis with extensive supporting data, see our Basic Report.
· With respect to the geology, it has long been apparent to us that the ancient oceans of Mars almost certainly supported photosynthetic life. The very color of the planet, red, and the cause of that color, iron oxide, are almost enough to draw a firm conclusion. We were in Utah on August 7, 1996 when President Clinton made his announcement about a possible fossil found in a meteorite from Mars (ALH 84001). Putting aside the issue of whether or not the rock was a true fossil, as we looked outside our hotel room we noticed that most of the rocks there were red - due to iron oxide just as is the case on Mars. Why is there so much iron oxide in the rocks of Utah? Ancient seas there contained cyanobacteria. When it produced an abundance of oxygen, that oxygen reacted with iron in rocks to form the iron oxide (which is basically rust). Oxygen is a highly reactive gas that is not likely to form on its own (without photosynthesis) in an atmosphere in uncombined state. So it took life on Earth to color Utah red, and the same is likely true of Mars - so much so that the theory of panspermia often has life evolving first on Mars, and then being transferred to Earth via meteorites.