Scientists have proven that the most common bacteria on Earth can survive on exoplanets with an atmosphere of pure hydrogen.
Humanity has been seeking life in the Universe ever since it first discovered the vast expanses of space. One of the main questions that worries scientists – what does a living exoplanet look like and how much does it differ from Earth? Is there an atmosphere on it? Will the presence of living organisms change its composition? And, most importantly, the necessary conditions for life are the same conditions as earthly beings?
A team of researchers from MIT decided to start with bacteria. They incubated E. coli colonies in four vessels with different gas concentrations. In one there was ordinary air, in the other 100% hydrogen, in the third 100% helium and in the fourth mixture – 80% nitrogen and 20% carbon dioxide. According to an article published in the journal Nature Astronomy, Microorganisms could multiply in all four vessels, but in the air they did it at least twice as fast as in other gases.
The fact that bacteria can multiply in an airless environment is not surprising – a significant number of anaerobic organisms live on our planet, for some of which oxygen is poisonous. In addition, we know many examples of bacteria that can survive and multiply under the most extreme conditions, from hydrothermal sources in nuclear reactors. However, according to the researchers, if bacteria can survive in a 100% hydrogen medium, then with a high degree of probability they will take root on most rocky exoplanets known to us.
Why hydrogen? Astronomers believe that planets with a hydrogen atmosphere are much easier to identify and study than planets in which the atmosphere consists of heavier gases. New generation telescopes, such as the James Webb telescope, will help scientists in this. In addition, if bacteria release gaseous metabolic products during their life, telescopes can also capture them in the atmosphere.