Astrobiologists have been considering that the presence of this element in the atmosphere of an extrasolar planet would be a key biomarker that would point to the existence of some type of organism in it. However, a team of researchers from the National Institute of Natural Sciences of Japan has developed a new hypothesis in which they suggest that it would be possible to find worlds rich in abiotic oxygen , that is, of non-biological origin.
And, according to these experts in the journal Scientific Reports , there may be different chemical reactions capable of affecting the composition of the atmosphere. Nonio Narita, one of the coordinators of the study, from the Astrobiology Center of the aforementioned Japanese institution, points out that this would be the case of oxygen caused by the photocatalytic reaction of titanium oxide, which is very abundant on terrestrial planets.
On Earth, for example, if this phenomenon were to occur continuously on 0.05% of the surface, the same amount of oxygen present in the atmosphere would be produced. Even in the case of a system that had a star colder than the Sun, a photocatalytic reaction similar to the one described in this work and affecting 3% of the surface of an exoplanet would maintain the same amounts of atmospheric oxygen. That is, it is possible that there are lifeless extrasolar worlds with the same amount of oxygen as ours.
