Webb telescope finds possible signs of life on another planet

We might just have observed the first decent signs of life on another planet.

We have NASA's James Webb Space Telescope to thank for the new evidence, gathering data from 120 light years away, outside of the Milky Way in the constellation Leo. The excitement stems from the possible detection of dimethyl sulphide (DMS), a molecule that to our present knowledge is only produced by living organisms.

Most of the DMS in Earth's atmosphere comes from phytoplankton emissions, living as they do in marine environments.

And so the excitement is notched up since it is not only DMS, but also methane and CO2 that have been discovered on the planet in question (the catchily named K2-18b). This could well mean that the planet has a water ocean.

The technique used is an analysis of the light that passes through a planet's atmosphere, light that contains chemical signatures. By splitting the light into its frequencies, researchers can see if parts of the spectrum are missing, absorbed by atmospheric chemicals.

Although this needs to be confirmed (this sort of news can end up being disconfirmed), it is the first time that astronomers have detected DMS on such a planet.

"Upcoming Webb observations should be able to confirm if DMS is indeed present in the atmosphere of K2-18 b at significant levels,” explained Nikku Madhusudhan, an astronomer at the University of Cambridge and lead author of the paper announcing these results.

Although there is a high likelihood of life existing elsewhere, given the size of the universe (see my recent book—coauthored with Dr. Aaron Adair—that investigates this topic), the universe is so vast that it could be like searching for a needle in a near-infinite (or truly infinite) haystack.

The planet had already been a suspect: The Hubble Space Telescope, James Webb's predecessor, detected water vapor on K2-18b in 2019.

Other variables such as temperature will also have their say on the probability of life existing on this exoplanet (a star-orbiting planet from outside our own solar system). K2-18b is nearly nine times the size of Earth. This could complicate matters, though the truth is that we don't understand such planets all that well. Planets of this size ("sub-Neptunes") that aren't gaseous do not exist in our solar system, though they are the most common type of planet in the galaxy.

What is certain is that K2-18b is now on our radar, so to speak. This exciting news will inspire more research into this planet, and motivate astronomers to continue the search elsewhere. Watch this space. Or that unfathomably large one out there.