Is Mars Alive? Curiosity Uncovers Organics and Methane in Gale Crater

Mosaic of Curiosity made with its turret-mounted MAHLI imager. (NASA/JPL-Caltech/MSSS/J. Major) — *Mosaic of Curiosity made from images acquired with its turret-mounted MAHLI camera. (NASA/JPL-Caltech/MSSS/J. Major)*

While it’s not quite the “smoking gun” for evidence of life on Mars, the recent announcement of a detection of spiking methane levels by NASA’s Curiosity rover has certainly caught everyone’s attention – especially since the activity of microbes is one possible source for the presence of the compound, which has already been detected by spacecraft in orbit around Mars.

“This temporary increase in methane – sharply up and then back down – tells us there must be some relatively localized source,” said Sushil Atreya of the University of Michigan, a member of the Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”

Still, biological in origin or not, these findings are yet another milestone for the MSL mission.

“We have had a major discovery. We have found organics on Mars.”
– John Grotzinger, Curiosity lead scientist

Excerpted from a JPL news release:

Researchers used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion. Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

Mars Hand Lens Imager (MAHLI) image of a 0.6-inch-wide hole drilled in a rock target dubbed "Cumberland" (NASA/JPL-Caltech/MSSS) — Mars Hand Lens Imager (MAHLI) image of a 0.6-inch-wide hole drilled in a rock target dubbed “Cumberland” on May 19, 2013 (NASA/JPL-Caltech/MSSS)

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity’s findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

This illustration portrays possible ways that methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars. (Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan) — This illustration portrays possible ways that methane might be added to Mars’ atmosphere (sources) and removed from the atmosphere (sinks). NASA’s Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars. (Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan)

“We will keep working on the puzzles these findings present,” said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena. “Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?”

Read about these findings in a JPL news release here, and watch the video below for more: