One group found carbon-containing organic matter in 3.5-billion-year-old rock.
Researchers said the findings correspond with findings of traces of methane, a chemical produced by some organic life forms, in the planet’s atmosphere. On Earth, 1,800 out of every billion molecules in the atmosphere is methane, and 95 percent of it comes for biological sources: Burning fossil fuels, decomposing debris, burping cows. “Now we have data to confirm that there’s a seasonal cycle, suggesting the methane is being generated by something”.
The Gale Crater was once filled with water fed by streams.
Curiosity has been drilling since 2013. Previously, some scientists have said it would be destroyed by the oxidation processes that are active at Mars’ surface.
“This is the first time we’ve seen something repeatable in the methane story, so it offers us a handle in understanding it”, said Chris Webster of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, lead author of the second paper.
Several spacecraft including Curiosity have detected whiffs of this gas that “defied explanation”, Webster said.
The mudstone rock was drilled from the top five centimeters (two inches) of the Martian surface and heated in a miniature analysis lab located on board the rover.
“We’ve been able to rule out some of the more simple or accepted ideas of Mars’s methane”, Dr Webster said. “We can not distinguish that”. “[But] it could also be rock chemistry”.
Whether anywhere other than Earth has harboured life, perhaps even in microbial form, is one of the paramount questions in science. Background levels climb by a factor of three from winter to summer, indicating a repeating release of the gas.
Organic matter has been found on Mars in soil samples taken from 3 billion-year-old mudstone in the Gale crater by the Curiosity rover, NASA announced Thursday. The Wikipedia article on “organic matter” makes the point: “Organic molecules can also be made by chemical reactions that don’t involve life”.
But the deposits were much smaller than they had anticipated. The innumerable technological advances which space explorations have given us? Carbon-rich meteorites contain kerogen-like compounds, and constantly rain down on Mars.
Clathrates mightn’t explain the origins of the methane molecules themselves, but their involvement would go a long way in explaining annual shifts in methane concentration. The rock samples were analyzed by SAM, which uses an oven to heat the samples (in excess of 900 degrees Fahrenheit, or 500 degrees Celsius) to release organic molecules from the powdered rock. Again, without having a Mars rock in a laboratory on Earth for more detailed study, we can not say what processes formed these molecules and whether they formed on Mars or somewhere in the interstellar medium and were transported in the form of carbonaceous meteorites. The methane signal has been observed for almost 3 Martian years (nearly 6 Earth years), peaking each summer. The event would be aired live on NASA Television. “We didn’t want to fund an incredibly expensive mission and come up short again”. What is needed to find more clues is a mission to Mars with a deep drill.
The car-sized Curiosity rover was launched from Florida in November 2011. And, of course, there is always the chance that Martian methanogens still slumber in the planet’s subsurface even today, periodically awakening during clement periods to produce their gaseous calling-card.