NASA’s Curiosity rover has found new evidence preserved in rocks on Mars that suggests the planet could have supported ancient life, as well as new evidence in the Martian atmosphere that relates to the search for current life on the Red Planet, according to an announcement made by NASA on June 7. While not necessarily evidence of life itself, these findings are a good sign for future missions exploring the planet’s surface and subsurface.
The new findings – “tough” organic molecules in three-billion-year-old sedimentary rocks near the surface, as well as seasonal variations in the levels of methane in the atmosphere – appear in the June 8 edition of the journal Science.
Organic molecules contain carbon and hydrogen, and also may include oxygen, nitrogen and other elements. While commonly associated with life, organic molecules also can be created by non-biological processes and are not necessarily indicators of life.
“After 40 years of searching the Mars surface, scientists found clear evidence for complex organic molecules containing carbon and sulfur,” McIntosh said. “Such molecules are considered the building blocks of life. Life needs such material for food and life is made of such material, but other non-biological processes can make the discovered molecules so this is not proof of life or past life on Mars. What is exciting is where they found the organics – in clay sediments in an ancient dry lake bed at the center of Gale Crater.”
McIntosh noted that previously, scientists had looked for such organics at other locations on the Martian surface with no luck.
“This means we now know where to look with the next generation rovers that can dig down meters (rather than centimeters) beneath the dried clay of ancient lakes and oceans that populated Mars billions of years ago,” McIntosh added.
Having discovered these molecules preserved for potentially billions of years, McIntosh said scientists are excited by the prospect of finding even more complex organic molecules deeper down that may be more likely to come from only biological processes.
The European Space Agency and Russia have a mission, ExoMars, going to Mars with a rover that will be able to drill two meters down. Meanwhile, McIntosh said NASA Curiosity will keep scratching at the surface as it makes its way around the dry lake bed and up the mountain at the center of the lake.
“I do think that the results announced today should strengthen the case for further and more in-depth exploration of Mars as soon as possible,” McIntosh said. “Mars is one of our best chances to answer the question on everyone’s mind – is there life out there?”
Read the rest of NASA’s announcement.