Strange aliens could be hiding in gases, scientists say

Gases could be found relatively easily and quickly with existing equipment

Artist's illustration of a potential Hycean world, where methyl halide gases would be detectable in the atmosphere (NASA, ESA, CSA, Joseph Olmsted/STScI)

Alien life could be hiding in gases, researchers have said.

We could find extraterrestrial beings in gas on faraway planets that are very unlike our own, according to their new study.

The gases themselves have been relatively neglected as a possible place to search for alien life. But it could actually be relatively easy and quick to examine, the scientists say.

We could even do so by looking at exoplanets using Nasa’s James Webb Space Telescope, they said.

The gases themselves are called methyl halides. On Earth, they are usually made by bacteria, fungi, or similar – and they are made up of carbon and hydrogen atoms attached to a halogen atom.

It would not be possible to see them on Earth-like planets, which are too small and dim to see with the Webb telescope. But other worlds, known as Hycean planets, could be possible places to search.

“Unlike an Earth-like planet, where atmospheric noise and telescope limitations make it difficult to detect biosignatures, Hycean planets offer a much clearer signal,” said Eddie Schwieterman, University of California Riverside astrobiologist and paper co-author.

We don’t know what the life forms that would produce such gases would look like – but they might look totally different from anything we’ve seen before

“These microbes, if we found them, would be anaerobic. They’d be adapted to a very different type of environment, and we can’t really conceive of what that looks like, except to say that these gases are a plausible output from their metabolism,” Schwieterman said in a statement.

The work is described in a new article, ‘Examining the Potential for Methyl Halide Accumulation and Detectability in Possible Hycean-type Atmospheres’, published in The Astrophysical Journal Letters.