Bacteria could survive just under Mars's surface for 280 million years

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When bacteria are dried and frozen, arsenic they astir apt would beryllium conscionable nether the aboveground of Mars, they tin past the aggravated radiation that hits the Red Planet for hundreds of millions of years

Space 25 October 2022

By Leah Crane

Microorganisms whitethorn beryllium capable to past conscionable nether the aboveground of Mars for acold longer than researchers thought. In a caller acceptable of experiments, researchers recovered that dried-up bacteria could enactment live successful Mars-like conditions for up to 280 cardinal years, which would amended our chances of uncovering grounds for them if Mars ever hosted life.

Most previous experiments to trial whether microorganisms could past the aggravated radiation connected Mars person utilized hydrated bacteria astatine country somesthesia – the longest-lived of those were thought to beryllium capable to past for up to astir a cardinal years. Brian Hoffman astatine Northwestern University successful Illinois and his colleagues took a antithetic tack, desiccating a assortment of bacteria and yeast and freezing them earlier subjecting them to radiation akin to what a buried beingness signifier connected Mars would acquisition and measuring the damage.

“There’s this phenomenal multiplication of the absorption erstwhile you get escaped of the h2o and you chill everything down,” says Hoffman. It is akin to freeze-drying nutrient to marque it past longer. Mars is adust and cold, truthful it is apt that immoderate bacteria determination would beryllium arsenic well. The researchers’ samples were damaged truthful small by the radiation that they estimated the bacteria could past for up to astir 280 cardinal years.

If the freeze-dried bacteria were warmed up and exposed to h2o during that time, they would look from their dormant state. “It opens immoderate possibilities that you could get revitalisation if a meteor with immoderate h2o comes down and splashes connected the surface, it could regenerate,” says Hoffman. “The probability that it’s inactive live present has accrued from zero to the tiniest happening you could ideate – it’s non-zero, but it definite arsenic hellhole ain’t big.” It is estimated that Mars dried up astir 3 cardinal years ago, truthful adjacent the heartiest of bacteria are astir apt dormant by now.

This longevity could marque it easier for america to find preserved grounds of immoderate bacteria that erstwhile lived connected Mars, but it besides means that if we contaminate it with Earthly organisms, that contamination would beryllium practically permanent.

“If we contaminate the country that we onshore in, however bash we cognize whether what we find was determination earlier we got determination oregon whether it was thing we deposited?” says Hoffman. “If we can’t archer what’s ours and what’s theirs, truthful to speak, past it’s intolerable to archer whether determination was beingness there.”

Journal reference: Astrobiology, DOI: 10.1089/ast.2022.0065