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

TL;DR

- 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

> false positive possibility is very low

No, it means we will soon discover how these compounds form naturally. Would love to be wrong, of course.

Parent is a flare star

I meant (and I think the article meant) false positive of gas detection not life

Is dimethil something expected to be generated with really procaryote life forms, or only from those with more complexe structures?

Like the sun, I guess

> The observations also provided a tentative hint of dimethyl sulfide (DMS), a possible biosignature gas, but the inference was of low statistical significance.

From the source paper. It is a very important result but not definitive, false positive is still possible as well as us finding a new way in which DMS can form without a biological process.

Still freaking exciting and fantastic scientific achievement. JWST is already bearing incredible fruits.

> false positive possibility is now very low

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.

Maybe the are cooking a lot of paper over there. https://en.wikipedia.org/wiki/Kraft_process

If plankton farts them, it's natural too, right?

Thats what I'd like to know, is this the kind of process that we can _get_ to 6 sigma by more observation time? Or would we need other observations / thats "as good as it gets" for the Webb's capabilities?