Signs found that life may have existed on Mars before
Samples of rocks from Mars showed signs that once on the planet there could be life similar to Earth. The rock collected by the Curiosity rover contains a large amount of organic carbon, which corresponds to the amount in the samples from the Earth or even exceeds it. This is mentioned in a NASA statement.
Curiosity collected samples by drilling rocks in Gale Crater, probably a former lake that the rover has been exploring since 2012. Samples were obtained from rocks 3.5 billion years old.
The rover analyzed the fragments using a device that uses oxygen and high temperature to convert organic carbon into carbon dioxide. From the amount of carbon dioxide formed, it calculates how much organic carbon was contained in the original sample.
“Total organic carbon is one of several measurements [or indices] that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology. We found at least 200 to 273 parts per million of organic carbon. This is comparable to or even more than the amount found in rocks in very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than has been detected in Mars meteorites,” says lead author and NASA scientist Jennifer Stern.
Organic carbon – carbon bonded to a hydrogen atom – is a prerequisite for organic molecules that create and use all known life forms. However, organic carbon can also come from inanimate sources, such as meteorites and volcanic eruptions. Although previous studies have found organic carbon in Martian rocks, new measurements help to understand its total amount in organic compounds.
In addition to organic carbon, scientists have found other signs in Gale Crater that indicate the possibility of life. These include low acidity, the presence of chemical energy sources and chemical compounds such as oxygen, nitrogen and sulfur.
“Basically, this location would have offered a habitable environment for life, if it ever was present,” the scientists emphasize.