oh hey, wonderful. thank you!
Comment on Searching for signs of life on exoplanets is tough.
Legianus@programming.dev 1 day agoAstronomer here, the “life detection” on K2-18b was dimethyl sulfide (DMS) and which is and remains a marker for life. What you get from the James Webb Space Telescope (JWST) is raw data that needs to be treated and calibrated to some extent to be usable in scientific study. This is called data retrieval.
However, the lead scientist on this paper claiming they found DMS basically used his own very specific way to do it and found very very weak signals in that way. Other scientist tried to both reproduce it in the way he did it and also with their ways to retrieve the data, but couldn’t find anything. So it turns out, it was simply a misdetection.
chosensilence@pawb.social 15 hours ago
chosensilence@pawb.social 15 hours ago
also, may i ask a question? you say “is and remains” a marker for life. i am not well read about these things, is that because DMS is only observed as a biosignature here on Earth, or are you saying it couldn’t possibly have a nonbiological origin?
Legianus@programming.dev 14 hours ago
Sure. Generally, it is a marker for life as we see it being produced by living organisms on Earth and it also should vanish quickly from atmospheres if it is not replenished. However, as you correctly put it, there may always be a non-biological explanation as well for any of these marker. So far I know, DMS has no non-biological explanation so far and is seen as a biological marker still.
Alas, the possibility of it being proven non-biological or even (as happend here) not a real detection makes it even more important to get more data and be very careful about the statements made from it than as otherwise those statements and/or connected papers have to be corrected/retracted.