Scientists scheduled to attend a symposium at the upcoming meeting of the American Association for the Advancement of Science (AAAS) in St. Louis think it might be possible to discover evidence of life on Mars – especially if microbes or microfossils can be found in the most unlikely places on Earth.
Lake Brown in Western Australia is a small, highly acidic salt lake, an extreme environment with striking similarities to the martian surface. Researchers from the University of Missouri-Rolla and Central Michigan University traveled there last year to search for evidence of life.
Dr. Francisca Oboh-Ikuenobe will share some of the preliminary findings from Australia at a symposium, “More than a grain of salt,” during the annual meeting of the AAAS, Feb. 16-20, at the America’s Center in St. Louis. The UMR-led session on geomicrobiology – the interface between microbiology and geology – starts at 1:30 p.m. Friday, Feb. 17, and is one of approximately 200 symposia on the AAAS meeting calendar.
The session will be moderated by one of the lead UMR researchers on the Australia trip, Dr. Melanie Mormile, an associate professor of biological sciences who is an expert in microbes, especially the kinds found in salt crystals.
The UMR scientists say they were shocked by the environments at Lake Brown and other lakes in the region.
“It was red everywhere,” says Oboh-Ikuenobe, a professor of geology and geophysics at UMR. “I’ve never seen so much salt in my life. We were walking on salt crusts in very shallow water that stung our legs. It didn’t look like anything could live in there.”
But Oboh-Ikuenobe, Mormile and other team members did find evidence of microbial life in bubbles, foams and hydrogen sulfide odors. They also found pollen trapped in salt crystals, mostly pollen from small shrubs and herbs.
Lake Brown and other shallow, ephemeral lakes in Western Australia formed after the ocean retreated from the continent. Several of these lakes are acidic and hypersaline. Sometimes, according to Mormile, individual salt crystals manage to trap records of history in the form of microbial cargo – even in environments seemingly hostile to life.
Geomicrobiology isn’t limited to the study of salt crystals or extreme environments. The “More than a grain of salt” session will include presenters and attendees from across the nation who work in many sub-fields, including palynology (microfossils), geochemistry, geophysics, sedimentology and astrobiology.
“One question with regard to astrobiology is, if you take this research to Mars, what do you expect to see in the rocks?” asks Dr. Estella Atekwana, a professor of geology and geophysics at UMR who will also participate in the St. Louis symposium.
Atekwana studies bio-signatures in rocks, collecting data to determine if microbes have been present in the past. “It’s either life or it’s not,” she says. “In the case of Mars, we would need to know what to look for.”
With ample time to study evidence of earth-life found in acidic salt crystals, Mormile and Oboh-Ikuenobe think they might have a better idea of what to look for on Mars.
The UMR researchers agree that, right now, it would be impossible to get adequate samples from Mars through the deployment of a robotic rover. But they don’t discount the possibility of being able to collect the samples remotely, or through human visits to Mars, in the future.