"By mimicking those conditions, we got the microbes to repeat that behavior in the laboratory," Fisk added.
The microbes were collected from a lava tube near Newberry Crater in Oregon's Cascades Mountains, at an elevation of about 5,000 feet. They were within the ice on rocks some 100 feet inside the lava tube, in a low-oxygen, near-freezing environment. Scientists, including Fisk, have said that the subsurface of Mars could have similar conditions and harbor bacteria.
In fact, Fisk has examined a meteorite originating from Mars that contained tracks which could indicate consumption by microbes though no living material was discovered. Similar tracks were found on the rocks from the Newberry Crater lava tube, he said.
"Conditions in the lava tube are not as harsh as on Mars," Fisk said. "On Mars, temperatures rarely get to the freezing point, oxygen levels are lower and at the surface, liquid water is not present. But water is hypothesized to be present in the warmer subsurface of Mars. Although this study does not exactly duplicate what you would find on Mars, it does show that bacteria can live in similar conditions.
"We know from direct examination, as well as satellite imagery, that olivine is in Martian rocks," Fisk added. "And now we know that olivine can sustain microbial life."
The idea for exploring the lava tube came from Radu Popa, an assistant professor at Portland State University and lead author on the paper. Popa used to explore caves in his native Romania and was familiar with the environmental conditions. Because lava tubes are a sheltered environment and exist on both Earth and Mars, Popa proposed the idea of studying microbes from them to see if life may exist or could have existed on the Red Planet.
"When temperatures and atmospheric pressure on Mars are higher, as they have be
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Oregon State University