According to BBC News: In what may be a groundbreaking moment in science, a team of scientists from the University of Cambridge has found the strongest hints yet that life might exist beyond Earth. Using NASA’s powerful James Webb Space Telescope (JWST), researchers studied a faraway planet named K2-18b and discovered signs of gases that, on Earth, are only made by living things.
K2-18b lies 124 light years away—over 700 trillion miles—far beyond the reach of any spacecraft. It’s more than twice the size of Earth and orbits a cool red dwarf star. Though it’s impossible to visit, JWST can study the planet’s atmosphere by examining how light from its star passes through the gases surrounding it.
In their latest observations, the Cambridge team detected chemical signs of two mysterious gases: dimethyl sulphide (DMS) and dimethyl disulphide (DMDS). These molecules are found on Earth but are only known to be created by tiny ocean organisms like plankton and bacteria. If confirmed, this could be the most promising clue yet that K2-18b may host life in some form.
Professor Nikku Madhusudhan, who led the study, says this is a huge step forward. “This is the strongest evidence yet that life might be out there,” he said. “The amount of gas we detected is thousands of times more than what we see on Earth. If it really comes from life, this planet could be teeming with it.”
However, scientists are cautious. The evidence, while exciting, is still not strong enough to be called a discovery. Researchers aim for a certainty level of 99.99999%—a “five-sigma” result. Right now, they’re at “three-sigma,” or 99.7%, which still leaves room for doubt.
To rule out errors, the team is working with labs to see if these gases could form naturally without life. Some scientists think volcanoes or other strange geology could explain the gases. Others question whether K2-18b even has an ocean at all. It could be a hot ball of molten rock or even a mini gas giant with no surface.
Despite the debate, the discovery has created a buzz in the scientific world. Dr. Subir Sarkar, another team member, says the planet might have a vast ocean that could support life—but more data is needed. Other experts, like Scotland’s Astronomer Royal, Professor Catherine Heymans, agree that the signal is exciting but not yet proof of life.
Even with all the questions, the Cambridge team remains hopeful. “Decades from now, we may look back at this moment and see it as when the living universe came within reach,” said Prof. Madhusudhan. “This could be the tipping point—the moment we got closer than ever to answering the age-old question: Are we alone?”
