Life may survive in large hydrogen planetsDate: 14 May 2020 Tags: Space
Explorations for search for life on exoplanets via atmospheric ‘biosignature gases’ is accelerating. These explorations are motivated by the capabilities of the next generation of space- and ground-based telescopes.
According to the team, exoplanets with hydrogen in their atmospheres are a good place to seek out alien life. Hydrogen atmospheres are a desirable place to look for signs of life.
Hydrogen is so much lighter than elements like nitrogen and oxygen, which are present in Earth’s atmosphere. That means that hydrogen atmospheres extend much further into space, and are more easily studied with our telescopes.
Our present-day atmosphere is very different from the earth‘s original atmosphere, which was mostly hydrogen and helium with lesser amounts of ammonia and methane. There was no oxygen until the Great Oxidation Event.
The Great Oxygenation Event occurred when cyanobacteria living in the oceans started producing oxygen through photosynthesis. As they changed the atmosphere to an oxidizing atmosphere, almost all life on earth went extinct.
The small amount of hydrogen that remains today is consumed by certain ancient lines of microorganisms, including methanogens.
Methanogens are well-studied, and scientists know that they can grow in 80% hydrogen atmospheres, at least in labs. But, this new study has suggested that there aren’t many studies exploring how other microbes can tolerate hydrogen-rich environments.
Until now, astronomers were unable to study the atmospheres of small, rocky exoplanets. And while scientists have conjectured that planets should harbour hydrogen-rich atmospheres, no working telescope has the resolution to spot them.
But if next-generation observatories do pick out such hydrogen-dominated terrestrial worlds, the results show that there is a chance that life could thrive within.