天文学家在距离地球124光年的行星K2-18b上探测到两种可能由微生物产生的化学物质，这被认为是迄今为止最有希望的外星生命迹象，但科学家表示需要更高确定性才能确认。
Scientists are closer to knowing if we are alone. For centuries, they have looked into space for signs of alien life. Now, astronomers say they have detected two chemicals that provide the conditions for life. One scientist said the chemicals represent the potential fingerprints of life. On Earth, these chemicals are only produced by microorganisms. The chemicals are "the most promising signs yet" of life. The chemicals were found on a planet called K2-18b. This is about 124 light years from Earth. A scientist believes the planet might be a Hycean planet. This is a planet covered in water. The scientist said a Hycean world has an ocean "that is teeming with life". He said the data from K2-18b "fits" that kind of world. However, he was only 99.7% sure of that. He said he needed to be 99.99994% certain to be sure that we are not alone.