New strategy to detect alien life in distant exoplanets

In a new article by Astrophysical Journal Letters, researchers at the University of California, Riverside, describe these gases, which, They could be detected in exoplanet atmospheres with the James Webb space telescope (JWST).

Methyl halides

Called Methyl halides, these gases are composed of a methyl group, which contains a carbon and three hydrogen atom, united to a halogen atom such as chlorine or bromine. They are produced mainly on Earth by bacteria, sea algae, fungi and some plants.

A key aspect of the search for metilo halides is that The exoplanets that look like Earth are too small and faint to be seen with the JWST, The largest space telescope currently in space.

Instead, the JWST would have to Look for larger exoplanets that orbit small red starswith deep global oceans and dense hydrogen atmospheres, called Hycean planets. Humans could not breathe or survive in these worlds, but certain microbes could prosper in such environments.

“Unlike a planet similar to Earth, where atmospheric noise and the limitations of telescopes hinder the detection of biofirms, the Hycean planets offer a much clearer signal,” Eddie Schwieterman, an astrobiologist of the UCR and co -author of the article, offered in a statement.

Researchers believe that the search for methyl halides in Hycean worlds is an optimal strategy today.

“Currently, oxygen is difficult or impossible to detect on a planet similar to Earth. However, methyl halides in Hycean worlds They offer a unique opportunity for detection with existing technology”Said Michaela Leung, a planetary scientist at the UCR and first author of the article.

In addition, finding these gases could be easier than looking for other types of biofirms life indicative. “One of the great advantages of looking for methyl halides is that they could potentially be found in just 13 hours with James Webb. This is similar or much less than the telescope time that would be needed to find gases such as oxygen or methane, ”said Leung. “Less time with the telescope means that it is cheaper.”

Although life forms produce methyl halides on earth, Gas is in low concentrations in our atmosphere. Because the planets hycean have such a different atmospheric composition and orbit a different type of star, Gases could accumulate in their atmospheres and be detectable at light years away.

Anaerobic microbes

“These microbes, if we found them, would be anaerobic. They would be adapted to a very different type of environment, and we cannot really conceive what that would be, except to say that these gases are a plausible result of their metabolism, ”said Schwieterman.

The study is based on previous research studying different gases biofirms, including dimethyl sulfide, another possible indication of life. However, methyl halides seem particularly promising due to their strong infrared light absorption properties, as well as their high accumulation potential in an atmosphere dominated by hydrogen.

While James Webb is currently the best tool for this search, future telescopes, such as the European Life mission proposal, could further facilitate the detection of these gases. If Life launches in the 2040s, as proposed, he could confirm the presence of these biofirms in less than a day.

“If we started to find methyl halides on multiple planets, I would suggest that microbial life is common throughout the universe,” said Leung. “This would transform our understanding of the distribution of life and the processes that lead to its origin.”