Mars contains so much radiation that any sign of life would be buried at least six feet underground.

The search for life on Mars may have become more complex.

As hikers like Curiosity and Perseverance clean the surface for traces of ancient life, New evidence reveals that we may have to dig deeper to find them.

Any evidence of amino acid residues from a time when Mars was habitable It was probably buried at least two meters underground.

This is because Mars, with its lack of magnetic field and thin atmosphere, is subject to a much higher dose of cosmic radiation on its surface than Earth. We know, and we know that cosmic radiation kills amino acids.

Now, thanks to experimental data, we also know that this process takes place on very short time scales, geologically speaking.

“Our results indicate that amino acids are being destroyed by cosmic rays in Martian surface rocks and regolith at a much faster rate than previously thought.”says physicist Alexander Pavlov of NASA’s Goddard Space Flight Center.

“Current roaming missions on Mars are about 5 centimeters across. At those depths, it would only take 20 million years to completely destroy amino acids. Adding perchlorate and water increases the rate of amino acid destruction.” Add.

Cosmic radiation is actually a major concern for Mars exploration. The average person on Earth is exposed to about 0.33 millisieverts of cosmic radiation annually. On Mars, this annual exposure can exceed 250 mSv.

This high-energy radiation, caused by solar flares and energetic events such as supernovae, can penetrate rocks, ionizing and destroying any organic molecules it encounters.

Mars is believed to have had a global magnetic field and a thicker atmosphere, like planet Earth. There is also a lot of evidence That liquid water once settled on the surface of Mars in the form of oceans, rivers, and lakes.

This combination of features indicates that Mars would have been habitable (perhaps frequently) in the past.

One sign that could indicate the habitability of Mars is the presence of amino acids. These organic compounds are not biological fingerprints, but ratherSome of the basic building blocks of life.

Amino acids combine to form proteins and have been found in space rocks, such as the asteroid Ryugu and the atmosphere of comet 67P. And therefore, It’s not a definitive sign of life, but finding it on Mars would be another clue that life might even appear there, one day.

Pavlov and his team wanted to better understand the possibility of finding evidence of amino acids on Mars, so they designed an experiment to test the potency of these compounds.

They mixed amino acids with mineral mixtures designed to simulate Martian soil, consisting of silica, hydrated silica, or silica, and perchlorate (salts), and sealed them in test tubes that simulated the Martian atmosphere, at varied temperatures similar to those. on Mars.

The team then irradiated the samples with ionizing gamma radiation to mimic the dose of cosmic radiation expected on Mars over a period of about 80 million years. Previous experiments only destroyed amino acids, with no soil mimics. This may have given an inaccurate age for the amino acids.

“Our work is the first comprehensive study in which the destruction (radiolysis) of a wide variety of amino acids under a variety of Mars-related factors (temperature, water content, and perchlorate abundance) has been studied and radioactive degradation rates have been compared.” , Pavlov says

“It turns out that the addition of silicates and especially silicates with perchlorate significantly increases the rates of amino acid destruction.‘ adds the scientist.

This means that any amino acids that were present on Mars around 100 million years ago are long gone, radiating into nothingness.

Since the surface of Mars has been inhospitable to life as we know it for much longer, billions of years, not millions, The few centimeters that curiosity and persistence can dig into are unlikely to yield amino acids.

Both rovers have found organic materials on the surface of Mars, but because the particles may have resulted from non-biological processes, they cannot be considered evidence of life. Furthermore, the team’s research shows that these molecules may have changed dramatically since their formation by ionizing radiation.

There is also other evidence to suggest that the research team could be onto something. From time to time, material under the surface of Mars reaches Earth. In fact, amino acids are found in it.

“We identified several straight-chain amino acids in the Antarctic Martian meteorite RBT 04262 at the Analytical Biology Laboratory at Goddard that we believe originated on Mars (not contamination from Earth biology), although the mechanism of formation of these amino acids is in RBT 04262. Still Exist Unknown. Without Explanationsays NASA Goddard astronomer Danny Glavin.

“Because meteorites from Mars are typically ejected from depths of 1 meter or more, it is possible that the amino acids in RBT 04262 are shielded from cosmic radiation,” AgWater.

However, we may have to wait until we have more Mars exploration tools to learn more.

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