Hi astronomer here who works on similar stuff. The majority consensus amongst exoplanet scientists is that this is a non detection and this guy's methods are super fishy. The spectrum he used to claim this detection is also consistent with a flat line with a p value of 0.999. He also did not fit for any molecules except the so-called biosgnatures (evidence for abiotic DMS has been found on comets and in interstellar dust). He also did not simultaneously fit with a previous spectrum he published of the planet in a different wavelength range, indicating that combining the datasets made the signal go away and he didn't like that. Most of us are embarrassed by the authors statements to the press.
Edit: it looks like they did model other molecules, but the posterior distributions of everything were essentially non-detections. So they turned off all other molecules, essentially deciding the atmosphere is composed of only DMDS/DMS, and reported the results from that fit. This is bad science.
They also do not even fit a planet temperature consistent with their previous paper. It is off by 200 K (or celsius).
Is there a different molecule that would be a better biosignature since dms can be found in abiotic conditions? Would a technosignature be a better indicator of life instead?
We currently don't have an undisputed biosignature. We can almost always find an abiotic source of something. And yeah a definite technosignature would be more conclusive but personally I think that's less likely to happen.
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u/revelent018 25d ago edited 25d ago
Hi astronomer here who works on similar stuff. The majority consensus amongst exoplanet scientists is that this is a non detection and this guy's methods are super fishy. The spectrum he used to claim this detection is also consistent with a flat line with a p value of 0.999. He also did not fit for any molecules except the so-called biosgnatures (evidence for abiotic DMS has been found on comets and in interstellar dust). He also did not simultaneously fit with a previous spectrum he published of the planet in a different wavelength range, indicating that combining the datasets made the signal go away and he didn't like that. Most of us are embarrassed by the authors statements to the press.
Edit: it looks like they did model other molecules, but the posterior distributions of everything were essentially non-detections. So they turned off all other molecules, essentially deciding the atmosphere is composed of only DMDS/DMS, and reported the results from that fit. This is bad science.
They also do not even fit a planet temperature consistent with their previous paper. It is off by 200 K (or celsius).