Magma may be profoundly lethal to humans, but the microbes under Geldingadalur are “probably loving it,” Moreras Marti says.
The Martian surface has long been an irradiated desert unsuitable for life. But what is happening at Geldingadalur today occurred on Mars, and is still possible. At any point during the past 4.5 billion years on Mars, whenever hot rock met water, underground hydrothermal networks would crop up. Being shielded from the deadly radiation bombarding its surface, these subsurface hideaways would be relatively habitable environments.
Mars was also considerably wetter when it was young, with a thicker radiation-blocking atmosphere. Long ago, microbes could have existed on the surface.
There, they would have been periodically cooked by sterilizing lava flows, which is exactly what’s happening at Geldingadalur today. The lava is killing off preexisting microbial life in the soil. Over the coming months and years, a brand-new ecosystem will rise out of the ashes of the old.
That’s one of the reasons why Hamilton, the planetary scientist, is there. When signs pointed toward an upcoming eruption on the peninsula, Hamilton and his colleagues sprang into action. “As soon as we saw the first earthquake swarms, we basically went out sampling all of the different areas to get an idea of what the baseline microbial ecology would be,” he says.
Hamilton and others will continue to take microbial samples from the soil and also from the air, as invading microbes may prefer gliding as opposed to swimming. (Samples may need to be taken from people’s boots too, Hamilton says, to try and spot any stowaways—a distinctly earthly, not Martian, issue.)
Scientists will also sample the lava itself. Mere weeks after Iceland’s Eyjafjallajökull eruption in 2010, scientists found not only that microbes had colonized the surrounding soil, but that they were living on the new lava flows themselves. “The lava was still hot,” says Mario Toubes-Rodrigo, a microbiologist at the Open University, in the United Kingdom, who explained that the visiting scientists had to be extremely careful. “I think a couple of their boots also melted.”
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But perhaps most important, the researchers will be able to trace the evolution of underground ecologies from the very moment a new habitat appears. That makes the subsurface shenanigans at Geldingadalur a rare and nearly ideal biological simulacrum of what may have once happened, or may still be happening, on Mars.
The eruption could fizzle out in the coming days or weeks. Conversely, it could continue for years, perhaps decades, much like the 35-year Pu‘u ‘Ō‘ō eruption on the flanks of Hawaii’s Kīlauea volcano. If so, this site will become a draw for planetary scientists and astrobiologists alike: a long-lived, safe and easily accessible natural laboratory in which to better understand two planets for the price of one eruption.
There is one crucial difference, however: the scale of the events. Mars’s lava flows were jaw-droppingly prolific, many with enough lava to bury a landmass the size of the U.K. in a matter of weeks. That makes the Geldingadalur eruption a “model-scale lava field,” says Tobias Dürig, a volcanologist at the University of Iceland. It’s a Martian eruption in miniature.
All things considered, that’s probably for the best.
This post appears courtesy of Quanta Magazine.