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BBC News: Scientists find 'strongest evidence yet' of life on distant planet

Hyperion 2.0

Hyperion 2.0

Pronouns
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An interesting finding was just announced, findings are still preliminary though.

Scientists find 'strongest evidence yet' of life on distant planet

Scientists have found new but tentative evidence that a faraway world orbiting another star may be home to life.

A Cambridge team studying the atmosphere of a planet called K2-18b has detected signs of molecules which on Earth are only produced by simple organisms.

This is the second, and more promising, time chemicals associated with life have been detected in the planet's atmosphere by Nasa's James Webb Space Telescope (JWST).

But the team and independent astronomers stress that more data is needed to confirm these results.
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My first reaction to this is "Either there's life, or we eventually figure out some novel geochemistry that can occur on other planets."

Either way, this shows promise.
 
Color me extremely unimpressed.

Firstly because "we know, on Earth, of no inorganic way of making that compound" does not me that there aren't.

And, in my eyes, even more important: their claimed detection is dubious at best. Sure, you can fit a model that show DMS in there; but the data is so noisy that you could also fit models without it.
 
From what I've heard, there's even more cause for skepticism, as the paper apparently heavily references and cites other papers by the lead author. Which isn't a great sign as to the validity of the claim, especially as the cited studies are themselves not particularly strong.
 
Vyslanté said:
Color me extremely unimpressed.

Firstly because "we know, on Earth, of no inorganic way of making that compound" does not me that there aren't.

And, in my eyes, even more important: their claimed detection is dubious at best. Sure, you can fit a model that show DMS in there; but the data is so noisy that you could also fit models without it.
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From the SB thread:
About that here. In particular:
A year ago, researchers reported a detection of DMS on the comet 67P/Churyumov-Gerasimenko — hardly a location brimming with life. (The team found the signal in archival data from the European Space Agency's Rosetta mission.) In September of last year, a team of researchers reported that in lab experiments, they were able to produce DMS by shining UV light on a simulated, hazy exoplanet atmosphere. This suggests that the reactions between a star's photons and molecules in a planet's atmosphere could provide a nonbiological way to produce DMS. And this February, a team of radio astronomers reported the detection of DMS in the gas and dust between stars. All of these results challenge the idea that DMS is a clear sign of life.
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DMS is a biomarker by Earth standards, but this does not mean that DMS is a definitive indicator of Space Phytoplankton elsewhere in the universe. Lab experiments aren't perfect analogues of stellar radiation-planetary atmosphere interactions, but they do show that abiotic production of DMS is far from impossible--and given just how wacky exoplanet atmospheres and weather can be, it's likely more possible than we'd initially suspect. The ESA conducted pretty extensive studies of Comet 67P with the Rosetta spacecraft, and they've found DMS there as well--yet there's no Space Algae living it up on that cometary nucleus.
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TBH the DMS levels being thousands of times higher than what life on earth produces strongly implies to me that it isn't life making it. Or there is some measurement error.

stairmaster said:
very exciting also very bleak from the great filter perspective.
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Hyperion 2.0 said:
How so?
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Yeah this would at absolute best be evidence that development has reached microbial single celled life stage on multiple different worlds. From our sample size of n=1, it looks like that happened nearly as soon as the earth stopped being molten, but things like oxygenation+multicellular life and intelligent life were both steps that took billions of years of the prior status quo before they kicked off. It not particularly hard to argue that those steps are leaps which are impossible to make on most worlds harboring microbial life, and very unlikely in the remainder even if no apocalyptic events hit them.

The nightmare scenario is getting a communication signal from life at the same stage as us, especially if paired with mounting evidence for the viability of generation ships or von neumann probes.
 
Regardless of how conclusive DMS is as a biosignature, this is definitely interesting enough that we need to gather more data on the exoplanet. Even if there are good non-biological explanations, that doesn't rule out that this could be genuine.
firefossil said:
The nightmare scenario is getting a communication signal from life at the same stage as us, especially if paired with mounting evidence for the viability of generation ships or von neumann probes.
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I'd even narrow it to saying that the only nightmare scenario is if generation ships and Von Neumann probes are proved to be practical. There's too much of a possibility that life just can't leave its solar system or finds it too impractical.
 
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Correct me if I'm wrong but haven't we discovered traces of this chemical on other planets in our solar system as well? I could've sworn I've heard something about it on Mars at least
 
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