Life on Earth finds a way to exist in some of our Most extreme and unusual environmentsIt is possible that microbial life could have once made a living on the red planet neighboring us.
New lab simulations that simulate some of the harsh conditions this life would have faced suggest that there may be signs of these microbes, still hidden under meters of Martian mineral dirt for future rovers. ExoMarsTo find.
This is despite Any ancient life would have encountered challenges on what is now a desolate, freezing, and essentially airless planet – not to mention the difficulties we You might recognize them.
“If Martian life existed, even though viable lifeforms aren’t yet present on Mars,” Mars, their macromolecules Viral infectionsIt would be much more durable.” SaysUniformed Services University pathologist Michael Daly
“This increases the likelihood that future missions will reveal if there was ever life on Mars.”
Daly and colleagues exposed six microbes – including the most radiation-resistant bacteria known, Deinococcus radiodurans, And the yeast Saccharomyces cerevisiae – to the dry and frigid -80 °C (-112 °F) conditions similar to those found on Mars.
“There is no water flowing or significant water in Martian atmosphere so cells and spores will dry out.” SaysBrian Hoffman, Northwestern University Chemist
“It is well-known that Mars’ surface temperature is about the same as dry Ice, so it is certainly deeply frozen.”
The team bombarded dried and frozen bacteria with protons and gamma radiation to simulate cosmic radio.
Mars lacks the cosmic radiation protection that Earth has. Most of the radiation is blocked by our atmosphere and planet’s magnet field, which means that we only receive a fraction of the radiation that we receive on the surface. two chest x-rays.
Contrarily, if you were on the red-colored planet’s surface, you would be bathed. 40-50 times more radiation – that’s a Within six months, lethal dose.
This radiation level can damage amino acids, which are essential building blocks of life. previous researchIt took 2 meters (6.6ft) of ground to shield these molecules for approximately 80 million years, if we are lucky.
But Mars has been hostile to our understanding of life for billions upon billions of years, so any trace of it would have been beyond our reach.
The new studyResearchers found that the dried-out and frozen samples could be used for research purposes. D. radioduransIt could live much longer than previously thought. The bacteria was so strong that the team gave it the nickname Conan the Bacteria.
Based on their data, the team believes Conan the Bacteria can survive 1.5 million years with Mars dirt only 10 cm thick, or 280 million years if it is huddled 10m below the surface.
“Although D. radioduransThese buried objects in the Martian subsurface were not able to survive the 2 to 2.5 Billion years since Mars lost its water supply. Instead, these Martian environments have been altered by meteorite impacts and are frequently melted.” explains Daly.
“We propose that periodic melting could permit intermittent repopulation or dispersal.”
This raises concern about the possibility that life on Mars could be cross-contaminated with Earth’s. Horne, Horne, and their colleagues need to devise planetary protection measures. Caution.
“We concluded that terrestrial contamination on Mars would essentially be permanent – over timeframes of thousands of years,” says Hoffman.
This could make it more difficult for scientists to search for Martian life. If microbes were to have evolved on Mars, they might be capable of living up to the present day. It is possible that Mars samples returned could be contaminated by Earth.
Their research shows that there is still hope. Even though it is a slim oneFuture rovers might be able reach ancient microbial Mars life, This assumes that such life existed in a similar way to what we know, if at all.
This research was published in Astrobiology.
