PROOF of life on Mars may exist – but we need to dig deep underneath its surface, Nasa scientists claim.
If scientists want to find signs of ancient life on Mars, they may need to dig about 6.6 feet or more under its Martian surface, a new Nasa experiment suggests.
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That’s because any evidence of amino acids left over from a time when Mars may have been habitable is likely buried in the ground.
Scientists look for amino acids because they believe the chemical compounds played an important role in forming life as we know it, per the Scripps Research Institute.
Amino acids, which can be created by life and by non-biological chemistry, are also a key component in building life-essential proteins.
So why do we need to dig to find these molecules? The answer lies in Mars’ intense absorption of cosmic radiation.
Because Mars lacks a magnetic field, and its atmosphere is quite flimsy, its surface is subject to a lot of cosmic radiation.
This radiation, in turn, destroys amino acids.
“Our results suggest that amino acids are destroyed by cosmic rays in the Martian surface rocks and regolith at much faster rates than previously thought,” said Alexander Pavlov of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
“Current Mars rover missions drill down to about two inches (around five centimeters). At those depths, it would take only 20 million years to destroy amino acids completely.”
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Pavlov added that any addition of perchlorates and water would destroy amino acids even faster.
“20 million years is a relatively brief amount of time because scientists are looking for evidence of ancient life on the surface which would have been present billions of years ago when Mars was more like Earth,” Nasa explained in their statement.
In light of this new research, a new strategy is required when drilling shallow surfaces with rovers like Perservenace or Curiosity.
“Missions with shallow drill sampling have to seek recently exposed outcrops – e.g., recent micro craters with ages less than 10 million years or the material ejected from such craters,” said Pavlov.
It is believed that at some point, billions of years ago, Mars had a global magnetic field and a thicker atmosphere.
There’s also evidence that bodies of water like lakes and rivers once existed on the Martian surface.
These features suggest that Mars could have been habitable in the past.
As of right now, though, amino acids haven’t been found on Mars – but they have been discovered in meteorites, including one from the Red Planet.
“We did identify several straight-chain amino acids in the Antarctic Martian meteorite RBT 04262 in the Astrobiology Analytical Lab at Goddard that we believe originated on Mars (not contamination from terrestrial biology), although the mechanism of formation of these amino acids in RBT 04262 remains unclear,” said Danny Glavin, a co-author of the paper at NASA Goddard.
“Since meteorites from Mars typically get ejected from depths of at least 3.3 feet (one meter) or more, it is possible that the amino acids in RBT 04262 were protected from cosmic radiation.”
Organic matter has also been found on Mars by both Curiosity and Perseverance.
Still, this is not a definite sign of life since it could have been created by non-biological chemistry.
