There has always been this great debate among us earthlings as to whether we are alone in the universe or not. Probably not, suggests this recent Smithsonian article detailing the possibility of life in brine pools beneath the Martian surface. Researchers in this article determined that the mostly likely place to find life on Mars was in subsurface brine pools near the poles, due to lower temperature and higher pressure, which allows more oxygen to flow into the brine. Having oxygen in these pools create environments that are possibly sustainable to aerobic life on the red planet. Using sophisticated computer models, these researchers found a best case scenario and a worst case scenario. Best case, the amount of dissolved oxygen present is abundant enough to support the growth of more complex alien organisms, such as sponges. Worst case scenario, and the environment was still able to sustain some bacterial life.
According to a study published by Nature Geoscience, the typical concentration of dissolved oxygen that scientists believed many aerobic microbes and bacteria living in brine usually require to survive is actually lower than previously thought, leading to speculation that conditions on Mars could be habitable for alien microbes. This is extremely significant because even if amounts of dissolved oxygen are not as abundant as some models predict, life could still thrive if it required less to survive than the models predicted. Here on our big chunk of rock, we don’t have to worry about finding oxygen to breathe, as it is abundant in our atmosphere. This isn’t the case on our red neighbor’s surface; Mars’ atmosphere is thought to have lost almost all of its oxygen during a series of solar eruptions more than four billion years ago, stripping it of its carbon dioxide based atmosphere. This in turn caused its surface water to evaporate away. If life had existed on Mars prior to this, the new conditions certainly did not continue to support it. However, just as we have seen life thriving in extreme climates here on Earth, such as next to hydrothermal ocean vents or frozen in ice for ages, it is possible that life has adapted to live within the extreme conditions that has been predicted to exist on Mars. All aerobic organisms require oxygen for respiration, a process we are currently learning about in class. It was previously thought that water and life couldn’t exist on Mars considering its extreme temperatures and lack of atmosphere, but new research is digging deeper into the Martian landscape. New findings in studies such as those in the two aforementioned sources suggest that these subsurface brine pools do indeed exist, and that it is becoming evident that there is a high possibility that Martian microbes could exist, even thrive here.
Even complex organisms like ourselves had an ancient, primitive ancestor back at the very beginning of life on Earth some 3.8 billion years ago. If life on Earth is presumed to have begun in a very large puddle, who’s to say that it can’t happen on Mars?