A team of astronomers has re-examined the data suggesting life on a distant planet called K2-18b. The new analysis, conducted independently by three different teams, found no compelling evidence for the presence of life on this exoplanet. Initially, researchers had detected a molecule in the atmosphere that could have been created by living organisms, but further investigation has revealed that it was likely caused by other factors.
The debate surrounding K2-18b revolves around the challenge of observing distant planets. Astronomers use sophisticated tools to measure the wobble of stars and the gravity of planets orbiting them, which can provide clues about a planet’s atmosphere. In 2022, researchers began using the James Webb Space Telescope to peer at distant planets this way.
Two independent teams analyzed K2-18b data in 2024, finding strong signals of hydrogen, carbon dioxide, and methane in the planet’s atmosphere. However, one team found no clear evidence of dimethyl sulfide, a molecule that could be produced by living organisms. Another team, led by Dr. Luis Welbanks, considered alternative explanations for the signal, suggesting it could have been caused by other gases.
The debate is ongoing, with a third study scheduled to be published soon. The new observations are expected to include substantially more data than previously published and could potentially dispel much of the confusion surrounding K2-18b.
Source: https://www.nytimes.com/2025/05/23/science/astronomy-extraterrestrial-life-k218b.html