The James Webb Space Telescope (JWST) has found markers of possible abundance of life in the atmosphere of an exoplanet. K2-18 b has a mass 8.6 times that of Earth and a diameter about 2.6 times larger than our planet. It orbits in the “habitable zone” (Goldilocks)—a distance at which liquid water, a key ingredient for life, can exist on a planet’s surface—around a red dwarf star smaller and fainter than our Sun, located about 124 light-years from Earth in the constellation Leo. A Cambridge team studying the atmosphere of a planet called K2-18b has detected traces of molecules that on Earth are produced only by simple organisms. This is the second, and most promising, time that chemicals associated with life have been detected in the planet’s atmosphere by NASA’s James Webb Space Telescope (JWST). The Cambridge team discovered that the atmosphere appears to contain the chemical signature of at least one of the two molecules associated with life: dimethylsulfide (DMS) and dimethyldisulfide (DMDS). On Earth, these gases are produced by marine phytoplankton and bacteria. Professor Madhusudhan said he was surprised by the amount of the gas apparently detected during a single observation window. “The amount we estimate of this gas in the atmosphere is thousands of times higher than what we have on Earth,” he said. “So, if the association with life is real, then this planet is teeming with life,” he added.
