Scientists have detected what they say is the strongest evidence yet that life may exist beyond Earth. A Cambridge University team studying the planet K2-18b found signs of molecules associated with simple organisms.

Lead researcher Professor Nikku Madhusudhan told the BBC: “This is the strongest evidence yet there is possibly life out there. I can realistically say that we can confirm this signal within one to two years.” The James Webb Space Telescope detected chemical traces such as dimethyl sulphide, a gas produced by marine plankton on Earth.

Researchers estimate the level of this gas could be thousands of times higher than found in Earth’s atmosphere.

K2-18b lies 700 trillion miles away and is about 2.5 times Earth’s size, orbiting a red dwarf star.

Some scientists believe the planet contains a vast ocean, though others suggest molten rock or a gas giant structure.

More data is needed to confirm the signal and rule out non-biological explanations.

The research was published in The Astrophysical Journal Letters.