Finding carbon cycle on Mars, a breakthrough for possible microscopic life

NASA's work is a compilation of several years of results from the "Curiosity" mission on Martian soil. It could be 10 years before analyzing the samples being collected by the Perseverance mission.

Finding carbon cycle on Mars, a breakthrough for possible microscopic life
Samples being collected on Mars by the Perseverance mission rover. Image: UNAM

Finding traces of carbon in Mars rocks is not a new finding. The work published by NASA on the subject is a compilation of data in 2012, from when 24 soil samples were taken that have been analyzed inside the laboratory of "Curiosity", a robotic team that travels the Martian surface, clarified Patricia Guadalupe Núñez Pérez, a postdoctoral researcher at the Institute of Astronomy (IA) of the UNAM, at its Ensenada headquarters.

"It is something very interesting, to understand what is happening on Mars and how is its carbon cycle. Where this element is being generated and where it is going. Just as we have the water cycle and the carbon cycle on Earth, we are trying to understand the carbon cycle on Mars and these data give us insight into it," she said.

They are trying to investigate whether that cycle is generated in a similar way to how it occurs on Earth. "Carbon is a very stable atom, with very large molecules that form organic matter and are everywhere, also in living things. It is very interesting to know how it behaves," she noted.

When people talk about the possibility of life on Mars, they are referring to microscopic life: so far no macroscopic life has been found, nor fossils, which are still being searched for. Most likely, microscopic organisms, bacterial fossils, or something indicating that there were bacteria on Mars will be detected.

This evidence is being investigated in Gale Crater, where there was a lake and perhaps microorganisms lived in conditions similar to those on Earth. "We are trying to make homologies, to see how these primordial cycles work on Earth and if they could work the same way on Mars," she explained.

To continue locating evidence of life, the "Perseverance" mission is now on Mars, collecting samples of Martian soil and storing them in airtight containers that another mission will collect in approximately 10 years, said the astrobiologist.

Rover and breakthrough in finding carbon cycle on Mars, a possible lead to microscopic life.
Perseverance rover collecting samples of Martian soil. Image: UNAM

With the information obtained so far by "Curiosity", there is more solidity in the results and they can be compared. On Mars, there was more carbon 12 than 13. Isotope 12 is the most abundant found here on Earth, in more than 90 percent of the planet. If it was found there, it means that microorganisms may have existed at some stage of evolutionary life. These results are a type of verification, not one hundred percent because carbon 12 can also be produced abiotically.

"To have something more conclusive they would need to bring the samples back from Mars, which is what the Perseverance mission is doing, collecting samples from various places, leaving them packaged at specific sites, and then they will go get them on another mission, collect them and bring them back to Earth." Only by culturing those samples will we know if there are living microorganisms or fossils of them, she concluded.