New Molecules on Distant Exoplanet Hint at Possibility of Alien Life

Scientists have made a thrilling discovery that brings us one step closer to answering one of humanity’s oldest questions: Are we alone in the universe? Researchers from the University of Cambridge have detected molecules on a distant exoplanet that, on Earth, are only known to be produced by living organisms.

Using NASA’s James Webb Space Telescope, the team studied the atmosphere of K2-18b, a planet located 124 light-years away in the constellation Leo. What they found has sparked cautious excitement—chemical fingerprints of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), compounds that on Earth are typically made by marine microorganisms like phytoplankton.

While scientists emphasize that more research is needed before confirming any signs of life, these results mark a significant step forward. The potential presence of these molecules suggests that K2-18b could be an ocean-covered world with a hydrogen-rich atmosphere—conditions that might support life as we understand it.

“It’s the first time humanity has seen potential biosignatures on a habitable planet,” said Dr. Nikku Madhusudhan, lead researcher and astronomer at Cambridge. “It’s a revolutionary moment. This is the strongest evidence yet there is possibly life out there.”

Though the concentration of DMS and DMDS on K2-18b is estimated to be more than 10 parts per million—thousands of times stronger than Earth’s levels—scientists remain cautious. Dr. Madhusudhan stated that further theoretical and experimental work will be needed to explore whether such molecules could form through non-biological processes at such high levels.

K2-18b, discovered in 2015, is about 2.6 times larger than Earth and roughly eight times more massive. In 2019, scientists confirmed the presence of water vapor in its atmosphere, fueling speculation that it may be a “Hycean” world—an ocean planet beneath a hydrogen-rich sky.

While its red dwarf host star is much smaller and cooler than our sun, K2-18b orbits at a distance that places it within the habitable zone, where temperatures could allow liquid water to exist. Even so, experts caution that it’s far from being “another Earth.”

As the James Webb Space Telescope continues its mission to peer deeper into the cosmos than ever before, this discovery opens new doors in our search for extraterrestrial life. Confirmation, however, may still take years.

“We must be skeptical and keep testing,” said Madhusudhan. “That’s how science moves forward.”