Curiosity has discovered new "tough" organic molecules in three-billion-year-old sedimentary rocks on Mars, increasing the chances that the record of habitability and potential life could have been preserved on the Red Planet, despite extremely harsh conditions on the surface that can easily break down organic molecules.
The unmanned Curiosity rover has also found increasing evidence for seasonal variations of methane on Mars, indicating the source of the gas is likely the planet itself, or possibly its subsurface water.
The rover has also discovered traces of methane in Mars' atmosphere, which researchers reported in an additional paper in Science. But that explanation, too, suggests a provocative possibility; even if the organic molecules didn't come from life, they are exactly what life likes to eat.
The organic matter was found in pieces of solidified mud that was drilled out of the ground in Gale Crater on Mars by the Curiosity rover in 2015.
Attention, however this does not mean that life exists or has ever existed on the Red planet! Methane levels were measured over a period of 4.5 years, which showed an increase of methane during late winter in the southern hemisphere and late summer in the northern hemisphere. The molecules in the mudstone could have once enabled life to form in lakes when Mars still had liquid water on its surface and the methane could have been produced by life. The space agencies of Europe, Russia and many others, plan to drill deeper and more widely on the surface, which begs the question of what else they might find.
In addition to finding organic molecules in the rocks in Gale Crater, rover scientists are reporting another intriguing finding.
What has NASA actually found on Mars - and why is it important?
Scientists do not exclude a biological origin of the methane, due to the fact that its level changes from season to season. Besides, Curiosity is confident: "I have not yet found life on Mars, but the signs do not deceive ..."
The studies on methane and on organic molecules were published Thursday in the journal Science.
However, ten Kate says that it is not surprising to find organic matter on Mars because it can not be compared to items like pieces of flesh, dead cells or tufts of grass.
Christopher Webster, an atmospheric science research fellow at NASA's Jet Propulsion Laboratory in California, said it is possible existing microbes are contributing to the Martian atmospheric methane, said a report by news agency Reuters. The organic molecules were found in Gale Crater - believed to once contain a shallow lake the size of Florida's Lake Okeechobee.
NASA's Mars Helicopter, a small, autonomous rotorcraft, which will travel with the agency's Mars 2020 rover, now scheduled to launch in July 2020, to demonstrate the viability and potential of heavier-than-air vehicles on the Red Planet, is shown in this artist rendition from NASA/JPL in Pasadena, California, U.S. May 11, 2018. "We need to go to places that we think are the most likely places to find it".