The James Webb Space Telescope is set to turn its gaze towards a distant planet in another solar system on Friday to investigate one of the most tantalising hints of alien life ever discovered.
Below the constellation of Leo, too faint for the naked eye, is the red dwarf star K2-18, about half the size of our sun. In orbit around it is a planet called K2-18b, believed to be an ocean-covered world about 2.6 times the radius of Earth.
Hidden in its atmosphere, scientists have spotted signs of something that could ultimately show that the Earth is not alone in being home to life.
It is a gas called dimethyl sulphide (DMS). On Earth, the gas has just one source. It is “only produced
