Are there signs of life on alien planet K2-18b, or is it just a lot of hot air?

This artist's impression depicts what a water world with a hydrogen atmosphere, such as planet K2-18b, might look like. A. Smith, N. Madhusudhan/University of Cambridge hide caption toggle caption A. Smith, N. Madhusudhan/University of Cambridge An ocean world that's teeming with microbes — and who knows what other kinds of life — is currently the best explanation for some chemical signatures that the James Webb Space Telescope has spotted in the atmosphere of a distant planet. That's according to Nikku Madhusudhan of the University of Cambridge's Institute of Astronomy, who called his team's new findings "astounding." "These are the first hints we are seeing of an alien world that is possibly inhabited," he told reporters in a press briefing. "This is a revolutionary moment." It's also a harbinger of future claims about possible signs of life beyond our solar system that should become increasingly common, as scientists take advantage of the James Webb Space Telescope's unprecedented a...