The discovery of bacteria in Antarctica that live only on the chemicals in the atmosphere leads scientists to think that bacteria on other planets may be able to live the same way.
Bacteria in Antarctica may catalyze a change in how scientists search for life on other planets.
From people on the street to novelists to movie producers to scientists, people have wondered what aliens would look or be like. There have been some pretty imaginative and even downright terrifying imaginings of creatures from outer space, but the truth is, it’s more likely that what we’ll find are aliens in the form of microbes. So far, however, we haven’t really found any trace of alien life, microbial or no. But what if we’ve been looking in the wrong places?
In 2014, a team of researchers wanted to find out how microbes managed to survive in the extremely inhospitable environment of Antarctica. They discovered two previously unknown bacteria, WPS-2 and AD3, which may influence a shift in the search for alien life.
Robinson Ridge one of the sites where researchers collected soil samples [Photo by UNSW]
These organisms, amazingly, can survive only on hydrogen, carbon dioxide, and carbon monoxide in the air. This opens up the possibility that other microorganisms may be able to survive in environments that are as harsh as Antarctica, which is one of the most extreme environments on Earth.
Antarctica has below zero temperatures, so low that the highest Antarctic temperature ever recorded is -12.3 degrees Celsius. It also has high levels of ultraviolet radiation exposure, as well as small amounts of nitrogen, carbon, and water. Thus, it’s not really all that hospitable to life.
Even so, according to the study, there’s a “surprising diversity” of microbial life thriving in Antarctica. The researchers collected soil samples from ice-free sites along the Antarctic coast to get an idea of the kind of life that lived in the area. Upon reconstructing the genomes of the microbes, the researchers discovered the existence of WPS-2 and AD3 for the first time.
The microorganisms in Antarctica are living in conditions similar to those present on some moons and exoplanets. “The big question has been how the microbes can survive when there is little water, the soils are very low in organic carbon and there is very little capacity to produce energy from the sun via photosynthesis during the winter darkness,” said Belinda Ferrari, one of the researchers. “We found that the Antarctic microbes have evolved mechanisms to live on air instead.”
Mars is the prime candidate in the search for alien life, but other planets and moons may bear consideration as well.
How, then, are these microbes able to live on so little? The answer is in the genes of the microbes themselves. Their genes make it possible for them to quickly and easily take gases from the air to keep themselves alive.
Scientists have a list of conditions that are necessary for life to exist on another moon or planet. One of these conditions is the presence of liquid water. However, if microbes were able to live without water, it would open up a lot of new possibilities in the search for extraterrestrial life.
Of course, it’s still possible that life on other planets won’t be like life on Earth at all. However, understanding bacteria like WPS-2 and AD3 may help us take a different approach in the search for alien life. It’s possible that planets and moons that have previously been taken out of consideration may be given a second chance.
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