The news concerning Mars' capability to sustain living organisms just got better. Astrobiologists now say that microbes can survive the harsh parameters of the thin atmosphere on the Red Planet. In fact, a new study has determined that certain microbes, if given the opportunity to proliferate in areas on Mars that once hosted water, could actually tolerate the extremely thin atmosphere.
Astrobiology magazine reported this week that Rebecca Mickol, an astrobiologist at the Arkansas Center for Space and Planetary Sciences at the University of Arkansas in Fayetteville and lead author of the microbe study, and her team had found that microbial life could indeed survive conditions on Mars. Working on the idea that microbes inhabit nearly every known environment on Earth, Mickol reasoned that there was no reason to think that it could not also survive on Mars.
"In all the environments we find here on Earth, there is some sort of microorganism in almost all of them," Mickol said. "It's hard to believe there aren't other organisms out there on other planets or moons as well."
Astrobiologists and other scientists have found in the myriad photos and copious data sent back from Mars that the planet at one time, according to the evidence, was covered with rivers, lakes, and even one massive ocean in the billions of years since its formation. However, today Mars is primarily a dry, red, rocky world with nearly no atmosphere and no water on its surface. Still, combined with evidence of the planet once having had water, Mickol was inspired by the discovery of methane in Mars' atmosphere.
"On Earth, most methane is produced biologically by past or present organisms. The same could possibly be true for Mars. Of course, there are a lot of possible alternatives to the methane on Mars and it is still considered controversial. But that just adds to the excitement."Methane can be produced via volcanism, so evidence of the capability of survival is not evidence of life on Mars, and there is evidence of the geological process on the Red Planet, but methane, or natural gas, is also produced by the breakdown of organic matter. This is done by methanogens, some of the most simple and ancient living organisms on Earth. Methanogens do not need oxygen to survive (they are known as anaerobes), and Mickol's team set out to determine whether or not the microorganisms could survive in Mars' extreme atmosphere.
Truth to tell, Mickol, senior author of the study Timothy Kral (astrobiologist at the University of Arkansas at Fayetteville), and their team were up against a Martian atmosphere where, if water were to exist anywhere near the surface, it would constantly battle being boiled away by the high pressure produced by its thinness. Mickol and company noted that if microbial life on Mars existed, it would likely be found beneath the surface.
So the researchers kept their environments for the microbes oxygen-free (due to it being fatal to the organisms), testing four different types of anaerobic methanogens. The study lasted about a year and found that the observed methanogens all survived exposure to pressures down to roughly six-thousandths of Earth's surface pressure, with the duration of survival varying from three to 21 days.
Mickol said, "These experiments show that for some species, low pressure may not really have any effect on the survival of the organism."
The study has again shown promise that Mars could today -- or may have one day in far distant past -- been habitable, even if the life there might have been microscopic.
The news comes on the heels of the announcement that Russia's Rocosmos space agency and NASA are in the planning stages of sending a mission to Venus, where scientists now believe that the super-heated and seemingly lifeless world might actually be home to living organisms as well. The Inquisitr reported earlier in the month that mysterious black bands of clouds in Venus' atmosphere, if certain conditions are met, might house microbes. The mission, tentatively scheduled for 2023, might include instruments to detect such living organisms, scientists say.
Life on Mars and Venus just might exist, albeit in microbial form. More and more studies, not to mention all the incoming data, are reinforcing the idea. And as long as there is hope of finding life on our sister worlds of Mars and Venus (or anywhere else in the Solar System, Milky Way, or Universe, for that matter), there will be those steadfastly searching for empirical evidence.
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