Future telescopes, like James Webb (right), will be able to monitor the atmospheres of distant worlds to find evidence of life. The earth (top left) is endowed with several atmospheric gases, demonstrating life (oxygen and ozone). A new study shows that for the early Earth (bottom left) a combination of excess methane and carbon dioxide will become an alternative sign of life.
With the activation of the space telescope, James Webb and other giants will have to find new strategies for finding life on other planets. Scientists from the University of Washington have shown a simple approach that seems much more promising than the detection of oxygen.
The idea of finding oxygen is a good method, since you cannot get a lot of oxygen without life. But you can not rely only on this criterion. In addition, if there is another life, then there is no certainty that it will produce oxygen. Such biochemistry may be rare at all.
The new study examines the history of earthly life in order to find times when the atmosphere contained a mixture of gases that were out of equilibrium and exist only in the presence of living organisms. In fact, oxygen production began almost recently. Thus, scientists have identified a new gas combination - methane plus carbon dioxide and minus carbon monoxide. It is necessary to find the abundance of methane and carbon dioxide in the world where there is liquid water on the surface and there is no carbon monoxide. Analysis shows that this combination would be a true allusion to life.
Methane is produced in different ways: asteroid attacks, repulsion from the inner surface of the planet, the reaction of rocks and water. It turned out that it would be difficult to create a lot of methane on a rocky terrestrial planet without the presence of living organisms.
If methane and carbon dioxide are found together (without carbon monoxide), then this chemical imbalance will alert you to the presence of life. The carbon atoms in the two molecules act as opposite levels of oxidation.
Also, all extreme levels of oxidation are difficult to pass without producing carbon monoxide, which does not accumulate in the atmosphere, where there is life (absorbs microbes). Scientists insist that the new gas combination can be used for next-generation telescopes.