A salt-loving Earth microbe grew for months in…

Image for: Could Earth's microbes surviving Mars-like subsurface conditions mean life could exist below Mars' surface today? (source: newscientist.com)

The Story

An Earth microbe can grow under selected Mars-like stresses, but Mars itself has not yet shown the water or life needed to sustain it.

The experiment shows that one salt-loving Earth organism can actively grow under a carefully selected combination of Mars-like stresses. That makes certain subsurface environments scientifically worth investigating, especially where salty liquid water might exist. It stops at plausibility: no liquid-water pocket has been found, and laboratory success cannot establish life on Mars.

What is establishedHaloferax volcanii reproduced and used chemical electron acceptors under low pressure, high salinity and oxygen-free conditions.
What remains openActual Martian temperatures, nutrients, water availability and combined chemistry may not match the laboratory setup.

The University of Florida experiment showed growth and reproduction over months under low pressure, high salinity and oxygen-free conditions with Mars-relevant chemicals.
The researchers designed the experiment around possible salty liquid-water pockets below Mars, but such pockets have not been found.
A review recommends searching Martian subsurface environments for chemically powered microbial metabolisms informed by Earth analogues.

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2 of 6 institutional

2 Journals & institutions
4 News reporting

Deeper Insight

Haloferax grew into biofilms, dense living films, under Mars-like stress. Life may not die on hostile worlds. It may hide beneath them.

For months, Haloferax volcanii, a salt-loving Earth microbe, reproduced in low pressure, brine and oxygen-free gas, even using perchlorate for energy. The lab did not find life on Mars, but it widened the map: the surface may be the wrong place to look. If briny refuges exist below, Mars could keep its biology behind a locked door.

What it could changeMars missions could search for living chemistry in salty subsurface pockets, not just ancient traces in exposed rock.
How it touches todayContamination control matters more when a hidden Martian refuge could resemble a lab-grown Earth microbe.
Our futureWe could miss living worlds by searching only where sunlight and open water make life easy to see.

Earth’s deep subsurface hosts diverse microbes in rock fractures, aquifers, sediments and permafrost, including organisms living with extreme energy scarcity.
Martian subsurface zones may be more habitable than the original Viking surface sites, and chemically based metabolisms are promising targets for life detection.
Earlier experiments found Earth microbes growing under some freezing, low-pressure, oxygen-free Mars-like conditions, while also highlighting contamination risks.

Part of a signalLife keeps looking possible in places we wrote off as dead.

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4 News reporting

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Journals & institutions. Published in a peer-reviewed journal, or from a university, government body, court or other institution.
News reporting. Journalism: newspapers, magazines and news sites.

Featured · Primary source · pmc.ncbi.nlm.nih.gov
Subsurface Life on Earth as a Key to Unlock Extraterrestrial Mysteries - PMC
Journal · peer-reviewed
# Subsurface Life on Earth as a Key to Unlock Extraterrestrial Mysteries Microbial Biotechnology. Published: 2025-12-01. Review. 7 citations. ## Abstract The first forms of life on Earth were microbial, preceding the evolution of multicellular life by more than two billion years. Based on our curren
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Analysis · arstechnica.com
Permafrost microbes survive conditions similar to those on Mars
News reporting
Permafrost microbes survive conditions similar to those on Mars - Ars Technica # Permafrost microbes survive conditions similar to those on Mars Relatives of bacteria found in vacuum-frozen meat handle low temps, pressures. John Timmer – Dec 27, 2012 8:00 am | 20 The thin atmosphere of Mars doesn't
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Analysis · doi.org
Life Detection in the Martian Subsurface: Advancements in Microbial Metabolic Research under Mars Laboratory and Field-Analog Conditions since Viking
Journal · peer-reviewed
# Life Detection in the Martian Subsurface: Advancements in Microbial Metabolic Research under Mars Laboratory and Field-Analog Conditions since Viking Astrobiology. Published: 2026-06-27. 4 citations. ## Abstract Following the Viking experiments in 1976, many of the original inferences of biologica
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A salt-loving Earth microbe grew for months in Mars-like brine, shifting the search for life below the surface.