Astronomers have detected potential signs of life on a distant exoplanet called K2-18 b after spotting two gases that, on Earth, are typically produced by living organisms.
In a study published in Astrophysical Journal Letters, researchers announced the discovery of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) in the planet’s atmosphere—compounds commonly released by marine phytoplankton and other microbes on Earth. These substances, they say, could be biosignatures, or indirect indicators of biological activity.
“This is a transformational moment in the search for life beyond the solar system,” said lead author Nikku Madhusudhan of the University of Cambridge’s Institute of Astronomy in a Reuters report. “We have demonstrated that it is possible to detect biosignatures in potentially habitable planets with current facilities. We have entered the era of observational astrobiology.”
The scientists were quick to clarify that this is not confirmation of alien life. Instead, they emphasized that the findings should be treated with caution until further observations are conducted.
K2-18 b, located about 124 light-years from Earth in the constellation Leo, is roughly 8.6 times more massive than our planet and orbits a red dwarf star in what’s known as the “habitable zone”—a region where liquid water could exist on the planet’s surface.
According to Madhusudhan, while there are ongoing efforts to find life in our own solar system—including investigations on Mars, Venus, and several icy moons—this marks one of the first times scientists have been able to analyze such potential from such a distant world.
