Scientists from Oregon State University have collected microbes from an icy “lava tube” in mountains in Oregon – similarly hostile to the Red Planet’s surface – and found common microbes thriving.
The research team said that the microbes “lived” on iron from a mineral found in rocks – a mineral, olivine, also found in volcanic rocks on Mars, and could survive low oxygen conditions and the total absence of organic food.
“This microbe is from one of the most common families of bacteria found on Earth,” said Amy Smith, a doctoral student at Oregon State University and one of the authors of the study.
“You can find its cousins in caves, on your skin, at the bottom of the ocean and just about anywhere. What is different, in this case, is its unique qualities that allow it to grow in Mars-like conditions.”
The Oregon State University scientists proved that microbes have adapted to deal with their harsh living conditions.
In a normal, room-temperature settings, with normal oxygen levels, the bacteria eat organic materials such as sugar.
But the researchers removed the food, turned down the temperature to near-freezing and lowered the oxygen, they turned to the food they survive on in the lava tubes – olivine, a common mineral found in volcanic rocks on Earth and on Mars – as its energy source.
Martin Fisk, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and an author on the study said:
“This reaction – where microbes <<feed>> on a common mineral from volcanic rocks – just hasn’t been documented before.”
In volcanic rocks directly exposed to air and at warmer temperatures, the oxygen in the atmosphere oxidizes the iron before the microbes can use it.
But in the lava tube, where the bacteria are covered in ice and thus sheltered from the atmosphere, they out-compete the oxygen for the iron.
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 Prof. Martin Fisk, have said that the subsurface of Mars could have similar conditions and harbor bacteria.
In fact, Prof. Martin 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,” Prof. Martin 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.
“And now we know that olivine can sustain microbial life.”