The Perseverance rover has just found a rock with possible signs of ancient life on Mars. It has already been hailed as the most important find ever during the exploration of the red planet
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Cheyava Falls is the name given to a rock found on Mars on 23 July 2024. It has spots and veins similar to rocks on Earth that contain signs of our ancient microorganisms. One of the researchers said that if he found it on our planet, he would expect to find traces of multicellular organisms in it. Obviously, if we ever find signs of life on Mars, there is no way we will find anything beyond microbes. This mysterious rock was encountered on the edge of a river valley called Neretva Vallis. When it was still filled with water, it flew to Jezero crater.
The Perseverance is designed as an astrobiology mission and has some instruments that can analyze this around a meter/3 feet long rock. It found organic materials and dark spots, which, if encountered on Earth, would indicate the presence of fossilized microorganisms. Similarly colored spots are associated with chemical reactions due to life’s metabolism. Microbes would feed on energy extracted from hematite widespread on Mars, converting it into iron and phosphate. This discovery is also a sign of ancient water flows in this area of the red planet.
This is not yet unequivocal proof of life on Mars, as perhaps non-biotic, higher-temperature chemistry could create similar features. We don’t know of a non-biological process that could lead to this rock looking this way.
It is speculated that the red planet used to be much warmer billions of years ago and had a thicker atmosphere with liquid water on the surface, where life could have emerged, or perhaps it was shared with our planet via frequent-at-the-time asteroid strikes that caused the ejection of crust into space. In this case, Earth’s life would be more likely to land safely on Mars than vice versa as Earth has a thicker atmosphere, and potential rocks with some microbes would be more likely to be burned during the landing.
This lucky find will make the NASA sample return mission to Mars more urgent. Its cost exceeded the budget, and it might not be launched until the 2040s, just as the researchers cannot wait to put their hands on such rocks and check them for fossils. The same could be done with a crewed mission that will not happen anytime soon.
No we have not found life on Mars. Yet.
The labelled release experiment on the Viking landers got positive results, which suggested the that metabolism had occurred. However, since other experiments onboard the landers got conflicting results, NASA made the decision to not announce that they had discovered life.
Gilbert Levin, the Principal Investigator on the Labelled Release experiment, and his colleague Pat Straat, have complained that the experiment and its results were sidelined in order that NASA could give a definitive yes or no answer to the question of whether life was detected.
Now it has seemed ever since this argument occurred, that NASA has avoided stating that the primary aims of their missions has been life detection. They have rather gone for a strategy of “follow the water”, as opposed to the thorny question of life being detected directly.
The revelation in 1996, that a meteorite discovered in 1984, called Alan Hills 84001, seemed to have wormhole-like structures within it, briefly caused a frenzy of excitement.
This meteorite almost certainly came from Mars before landing on Earth, therefore acting like cosmic joker to cause some excitement and give President Clinton something to talk about other than Monica Lewinsky and cigar usage.
Such was the excitement about this meteorite, that it became acceptable for NASA and astrobiologists to talk publicly about life on Mars again.
However, despite plenty of discoveries that suggest Mars might have had perfectly favourable conditions for life to have evolved, no actual evidence of life has yet been discovered.
But never say never! With some excellent forthcoming missions from NASA and ESA soon to be on the launchpad (not at the same time or on the same pad – that would be silly), this is an excellent time to learn about what the questions are. Fingers crossed we get some great science.
