NASA’s Curiosity rover has measured spikes of methane, an organic chemical, in the atmosphere around Mars, and has uncovered other organic molecules in its surface rock. Since most of Earth’s atmospheric methane comes from forms of life and the environment itself, officials are saying both findings may be a sign of past or present microbial life – albeit, a vague one.
“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, Ann Arbor, and Curiosity rover team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”
Scientists used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory twelve times in a 20-month period to detect methane in the atmosphere. During two of the months, in late 2013 and early 2014, four measurements averaged seven parts per billion; before and after that, figures averaged only .1% of that level.
In addition, Curiosity detected different Martian organic chemicals when it drilled into a rock, making it the first definitive detection of organics in Mars’ surface. Although, the organics could either have developed on Mars or been hauled to Mars by meteorites and comet impacts – thus, the identity of the organic material remains unknown.
“This first confirmation of organic carbon in a rock on Mars holds much promise,” said scientist Roger Summons, who works on the rover team.
Organic molecules, which are made up of carbon and usually hydrogen, are the chemical building blocks of life, though they don’t necessarily need life to exist. Seemingly, the samples of organic matter in the Red Planet’s atmosphere and in its rock illustrate that the planet may have, at the very least, once had conditions favorable to hosting life. The findings also show that modern Mars is chemically active.
“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?”
Curiosity is a part of NASA’s ongoing Mars research and preparation for a human mission to Mars in the 2030s.