ADDIS ABEBA – The Dallol volcano in northeast Ethiopia is an analogue for the early Mars, new research claims.
The discovery of living bacteria embedded in salt deposited in super-saturated and acidic hot water inside an Ethiopian volcano offers a viable analogue for possible life on Mars, researchers suggest.
The bacteria were found buried near a hydrothermal vent inside the crater of the still-active Dallol volcano in the Afar Regional State of Ethiopia.
A team of researchers led by Felipe Gómez from the Spanish Astrobiology Centre made the discovery after a two-year-long study on a sample they took in January 2017.
The environment, which features a water temperature of 89 degrees Celsius, an air temperature average of 38 degrees Celsius, and a highly acidic pH reading of 0.25, is recognized as one of the most life-unfriendly places on Earth.
It is also thought to be rather similar to conditions that existed early in the life of Mars when it was geologically more active: notably in the Gusev Crater, where NASA’s Spirit Mars Exploration Rover landed.
It was a comparison that Gómez and colleagues made recently, in a paper published in the journal Astrobiology.
“The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars,” they said.
The results are published in the journal, Scientific Reports.
Gómez and colleagues discovered tiny, spherical structures within the salt samples that had a high carbon content, demonstrating an unambiguously biological origin.
The microorganisms are 50-500 nanometers in diameter—up to 20 times smaller than the average bacteria.
In several cases, the microorganisms are surrounded by needle-shaped crystals, which suggests that the nanobacteria may play an active role in the salt deposits and the geochemical cycle at Dallol.
“The results from this study suggest the microorganisms can survive, and potentially live, within this extreme environment, which has implications for understanding the limits of habitability on Earth and on (early) Mars,” the researchers said.
They, however, said further studies need to be done to understand “how these nanobacteria survive in such an extreme environment and whether they play a role in geochemical cycling”.