Commonly, in their search for alien life, most scientists would get thrilled if they find a planet with oxygen and similar to Earth. However, in a recent study, a group of scientists from Johns Hopkins University revealed that oxygen is not the surest sign of extraterrestrial life when the element is found in the atmosphere of an exoplanet.
According to the simulations the scientists conducted in their lab, that reproduced the atmospheres of exoplanets, oxygen is not always a sign of life. The results of the study were published in the journal ACS Earth and Space Chemistry.
“Our experiments produced oxygen and organic molecules that could serve as the building blocks of life in the lab, proving that the presence of both doesn’t definitively indicate life. Researchers need to more carefully consider how these molecules are produced,” explained Chao He, an assistant scientist at the Johns Hopkins University’s Department of Earth and Planetary Sciences, and the leading author of the new study.
Planets With Oxygen Might Not Necessarily House Alien Life
Oxygen sums up for approximately 20% of the Earth’s atmosphere, and it is an accepted biosignature. However, researchers don’t know much about how various energy sources might trigger the right chemical reactions on exoplanet so that they can produce a biosignature such as oxygen.
During their experiments, the scientists managed to produce both oxygen and organic molecules that are precursors for sugars and amino acids which are the building blocks of life. However, in different scenarios, they generated oxygen without organic matter.
“People used to suggest that oxygen and organics being present together indicates life, but we produced them abiotically in multiple simulations. This suggests that even the co-presence of commonly accepted biosignatures could be a false positive for life,” explained Chao He, indicating that planet with oxygen might not necessarily house alien life.
With over seven years of experience in online journalism, Vadim is passionate about everything related to science and the environment. For us, he will thus cover climate, environment, and science news, among others.