“Most promising signs yet” of alien life on a planet beyond our Solar System

- K2-18b

- detected dimethyl sulfide and dimethyl disulfide, false positive possibility is now very low

- "produced by marine-dwelling organisms on Earth", possibility they were produced by other processes (unrelated to life as we know it) not high but maybe unknown unknowns

- other factors like distance from the star are in favor of life & water

- previous studies detected methane and carbon dioxide

It's not that low, unfortunately. From the article:

> They say their observations have reached the ‘three-sigma’ level of statistical significance. This means there's a 0.3% probability the detection occurred by chance. And to reach the accepted level that would mean scientific discovery, observations would have to meet the five-sigma threshold. In other words, there would need to be below a 0.00006% probability they occurred by chance.