Is there life on Mars? Its easily one of the greatest questions in science, and although theres no definitive proof just yet, a new study has evidence that suggestsits easily possible, despite the relative inhospitability of the Red Planet.
Our crimson neighbor used to be covered in free-flowing water and abundant oxygen, but this has all but disappeared now. On our own home planet, where you have water whether it is unbelievably hot and acidic or whether its locked up beneath kilometers of ancient ice you have life in microbial form.
Mars still contains both surface and subterranean ice, so surely there are some extremophile organisms scuttling about in its hydrated soils? Well, perhaps.
Just beneath the surface, these hypothetical microbes would be shielded from the high levels of radiation that permeates through the planets thin atmosphere. Unfortunately, theres a potential problem.
The atmospheric pressure on Mars is so low ranging from one-hundredth to one-thousandth of that found on Earths surface that the water will easily boil off, regardless of the extremely low temperature of the environment there. Boiling water, as you can imagine, is not conducive to life, even for extremophiles, whose DNA could be irreparably damaged.
Enter, the methanogens. These little guys and girls belong to the domain of archaea, extremely simple but resilient lifeforms often found in extreme environments. Methanogens, as the name implies, convert hydrogen into methane without using oxygen, in order to gain energy in a process known as anaerobic respiration.
Theyre everywhere from wetlands to inside the guts of mammals, including you. In fact, theyre part of the reason you yes, you may be so flatulent. They could also exist in pockets of water on Mars, but could they survive the boiling process that is so common there?
The Twin Peaks, as captured by the Mars Pathfinder. NASA/Caltech-JPL
A team at the University of Arkansas inFayetteville grabbed four species of methanogens and placed them in simulated Martian watery, soil-sprinkled environments, putting them under the exceedingly low pressures that youd expect to find on the real deal. They also made sure there was plenty of hydrogen gas in the water and almost no oxygen whatsoever.
Remarkably, after up to 21 days at pressures down to one six-thousandths of those found on Earth, all four species survived.
These experiments show that for some species, low pressure may not really have any effect on the survival of the organism, lead author Rebecca Mickol, an astrobiologist at the University of Arkansas, told Astrobiology Magazine.
Writing in the journal Origins of Life and Evolution of Biospheres, the team note that although they need to do more tests involving frigid temperatures, their experiments show that life on Mars is, indeed, a possibility.