The aliens have landed – but not on Earth. Rather, evidence of extraterrestrial life has landed on the sensors of the James Webb Space Telescope, or Webb for short. Webb is the most sensitive of all our instruments in space, and can monitor distant exoplanets outside our solar system.

For years, Webb has been on a mission to find biosignatures – traces of molecules that indicate the presence of organic material, living matter, on other planets. And the easiest molecules to detect from a great distance are gasses. Finding oxygen in the atmosphere of an exoplanet would be an indicator of life, but it’s a time-consuming and frustrating exercise.

Recently, Webb has turned to another group of gasses, methyl halides. These chemical compounds are produced by organisms like bacteria and algae, and are much easier to detect in larger exoplanets with atmospheres rich in hydrogen. These planets wouldn’t support oxygen breathing lifeforms like animals and humans, but certain microbes could thrive in such an environment.

And now we have the proof. NASA has confirmed the discovery of detectable methyl halides in the atmosphere of a giant Hycean planet. “There’s definitely something out there,” said Webb’s mission director. “We’re not sure what, but there must be living microbes or plant-like organisms producing all these halides!”

As soon as 2040, the European Space Agency will launch the LIFE mission, an even more powerful telescope, to confirm and extend the search. There are bound to be countless planets capable of supporting primitive or exotic life, waiting to be discovered.

But for now, Webb has taken the honours, and found the first proof of alien life.