(LOOTPRESS) – Astronomers have identified the strongest signs yet that life might exist beyond our solar system — and it’s coming from a planet 124 light years away in the Leo constellation.
Using data from the James Webb Space Telescope, an international team of researchers detected chemical traces in the atmosphere of exoplanet K2-18b that may point to the presence of microbial life. The findings, published in The Astrophysical Journal Letters, are being met with both excitement and caution across the scientific community.
Possible Biosignatures Found
The chemicals dimethyl sulfide (DMS) and dimethyl disulfide, found in K2-18b’s atmosphere, are key to the study. On Earth, DMS is produced only by life — mostly microscopic algae in the ocean — making it a possible biosignature, or indicator of life.
“This is the strongest evidence yet there is possibly life out there,” said Nikku Madhusudhan, the study’s lead author and an astrophysicist at Cambridge University. “I can realistically say that we can confirm this signal within one to two years.”
Despite the hopeful tone, Madhusudhan and his team stressed that more observations are needed to rule out non-biological explanations for the chemical traces.
A Planet in the “Goldilocks” Zone
K2-18b is a rare find among over 6,000 known exoplanets — it lies in the habitable or “Goldilocks” zone, where temperatures might allow for liquid water, a crucial ingredient for life.
Roughly 2.5 times the size of Earth and more than eight times as massive, the planet orbits its star every 33 days. In 2023, Webb detected methane and carbon dioxide in the planet’s atmosphere, marking the first carbon-bearing molecules found on a habitable-zone exoplanet.
Now, further observations using Webb’s mid-infrared instruments have revealed stronger signals of DMS, though the results still fall below the gold-standard five-sigma confidence level scientists require for a confirmed discovery.
Skepticism and Scientific Debate
Outside experts are urging restraint. Some point to past incidents — like previous claims of water vapor in K2-18b’s atmosphere that were later retracted — as reasons to hold off on drawing conclusions.
Others, like Oxford physicist Raymond Pierrehumbert, argue that the planet may be far too hot to support life, calling the surface conditions potentially “hellishly hot” and more likely to host lava oceans than alien microbes.
Madhusudhan, however, remains optimistic that K2-18b is a “hycean” planet — an ocean world with a hydrogen-rich atmosphere that may provide the right conditions for primitive, marine life.
What’s Next?
Madhusudhan estimates that just 16 to 24 more hours of telescope time could bring the data to the five-sigma level, possibly within the next few years. If confirmed, the implications would be groundbreaking.
“This could be the tipping point,” he said, “where suddenly the fundamental question of whether we’re alone in the universe is one we’re capable of answering.”
While the findings are still under investigation, one thing is clear — our tools for exploring the cosmos are more powerful than ever, and the search for life beyond Earth is reaching new heights.
