NASA’s Curiosity rover has made a significant discovery that may help scientists determine if there is, or ever was, life on the Red Planet.
Curiosity has detected temporary spikes in methane in the atmosphere of Mars, as well as other organics in rock samples collected by the rover, which has excited scientists about the prospects of finding evidence of life on Mars.
Researchers using the rover’s Sample Analysis at Mars suite of instruments detected fluctuations in the concentration of methane in the atmosphere of Mars over a 20-month period. They saw a tenfold increase in the concentrations of methane in the atmosphere on two separate occasions, with four measurements averaging seven parts per billion.
“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 Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”
Methane is of particular interest to scientists looking for evidence of past or present life on Mars, as it is a common waste product of living organisms with most of the methane on Earth coming from biological sources. However, methane can also be produced from abiotic sources, such as geologic activity.
“We can’t rule out the possibility of life on Mars now,” according to Curiosity participating scientist Danny Glavin. “It’s really exciting. There are other explanations, of course — they could come from asteroids or comets, or non-biological reactions.”
“The other possibility is that we’re looking at the chemical fingerprint of a Martian Biotia that died out,” Glavin added.
Curiosity also uncovered organic chemicals in a powdered sample the rover collected after drilling into a rock called Cumberland. This marks the first time that the detection of organics in Mars surface samples has been confirmed, according to NASA.
Researchers spent months confirming that the organic material they discovered was in fact from Mars and not transported with the rover from Earth. While some Earth-originating organics were found, mission scientists are confident in their discovery of Martian organics. Is it not yet known if these organic chemicals are indigenous to Mars or if they arrived on the planet via meteorites.
Organic molecules are essential building blocks of life. While the presence of organics on Mars is not direct evidence of life, either past or present, the latest findings do suggest that Mars is chemically active even today and may have once harbored conditions favorable to life.
“This first confirmation of organic carbon in a rock on Mars holds much promise,” said Curiosity participating scientist Roger Summons. “Organics are important because they can tell us about the chemical pathways by which they were formed and preserved.”
“We will keep working on the puzzles these findings present,” said Curiosity project scientist John Grotzinger 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?”