Scientists evaluating data and samples from NASA’s Curiosity rover from Gale Crater on Mars, the site of an ancient lake, have made a tantalizing new discovery: “total organic carbon,” a key ingredient for life, is surprisingly high in the Martian rocks that the rover was scanning.
Examining data from the Curiosity rover eight years ago, scientists found levels of molecules in Martian rocks comparable to those found in rocks from “little places” on Earth, a fascinating discovery that could have remarkable consequences for our understanding of ancient life on the red planet.
According to a NASA statement, this is the first time scientists have been able to measure the total amount of organic carbon in Martian rocks.
Organic carbon, which is carbon bonded to a hydrogen atom, is a prerequisite for organic molecules created and used by all known life forms.
Know the total amount of carbon in organic compounds
However, the discovery of organic carbon does not conclusively prove the existence of life on Mars, since these molecules can also come from non-living sources, such as meteorites and volcanoes. Even so, the new measurements – although previous studies have detected organic carbon in smaller quantities in Martian rock samples – allow us to know the total amount of carbon in organic compounds.
“Total organic carbon is one of several measurements [o índices] that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology,” said Jennifer Stern of NASA’s Goddard Space Flight Center and lead author of a new article published in Proceedings of the National Academy of Sciences (PNAS), it’s a statement.
From a perch in the shallow “Yellowknife Bay” depression, NASA’s Curiosity rover used its Right Mast Camera (Mastcam) to take the combined telephoto images in this geologically diverse panorama.
There is as much organic carbon in rocks on Mars as in those of the Atacama
“We found at least 200 to 273 parts per million organic carbon. This is comparable to or even more than the amount found in rocks from very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than that has been detected in meteorites on Mars,” he added.
The Mars Curiosity Rover’s mission is largely to find evidence of life and habitability on Mars. To do this, it studies the chemical and geological environment of the surface. In particular, it helps to unravel the role that water has played in the past. Measurement of total organic carbon is part of this mission.
Gale Crater: 3.5 billion year old mud rocks
In the new study, researchers evaluated data from the Curiosity rover’s assessment of samples drilled into 3.5-billion-year-old mud rocks in Gale Crater’s Yellowknife Bay formation, the site of an ancient lake on Mars.
Curiosity used its Sample Analysis at Mars (SAM) instrument in 2014, inside which it baked pulverized rock samples at high temperatures. The process converted some of the carbon to CO2, which allowed Curiosity to measure carbon isotope ratios, giving scientists insight into the original source of the material.
They found that organic carbon was part of this mud material and that, in addition to liquid water and organic carbon, the Martian crater had other conditions conducive to life, such as chemical energy sources, low acidity, and essential elements for life such as carbon dioxide. oxygen, nitrogen and sulfur.
“Although the results suggest that this carbon was largely refractory or mineral-bound, attesting to its conservation over billions of years, it remains to be determined whether there is chemical information preserved in it that indicates how it was formed and what processing may have done it.” altered since its deposition,” the scientists wrote in the study.
“Essentially, this location would have offered a habitable environment for life, if it was ever present,” Stern said.
However, according to Stern, the most likely hypothesis remains that the total organic carbon was the result of other non-living processes.
“Although biology cannot be completely ruled out, isotopes cannot be used to support a biological origin of this carbon either, because the range overlaps with igneous (volcanic) carbon and meteoritic organic material, which are the most likely to occur.” be the source of this organic carbon,” he concluded.
Edited by Felipe Espinosa Wang.