Atmosphere of this exoplaned is rich in hydrogen. Also it has likely different atmospheric pressure than we have on Earth. Doubtful there is any life form as we know it. I suspect best we can expect there is something like a primordial soup: a mix of relatively simple organic compounds.
“Most promising signs yet” of alien life on a planet beyond our Solar System
221–230 of 365 posts
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#222Earlier quoted context omitted.
Sadly it is still only a stop-gap measure. The sun is for all intents and purposes, dying a slow death.
Sure, but it may keep Earth habitable for an extra billion years.
Unfortunately it looks like we are more in the track to human inhabitable earth :(
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#223Let’s assume there is alien life on many planets beyond our solar system. Now what? What’s the practical benefit?
Let's assume I wake up tomorrow still alive. Then what? You're basically asking what's the meaning of life.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#224Earlier quoted context omitted.
Faster than light travel isn't needed (and IIRC doesn't occur in the series the dark forest name comes from). Spectacularly devastating weapons are definitely possible - redirect an asteroid into an inhabited planet and you're likely to kill most of its inhabitants; redirect enough and you can kill almost everything. That's not even getting into things like antimatter, gamma rays, etc. The dark forest hypothesis does…
> and IIRC doesn't occur in the series the dark forest name comes from The Trisolarians developed FTL travel while they were on the way to Earth, IIRC.
I tried to look it up. I think they didn't ever get FTL, based on https://www.reddit.com/r/threebodyproblem/comments/1blvikg/c... and https://forums.spacebattles.com/threads/trisolaris-in-wh40k.....
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#225K2-18 is a red dwarf. These stars often emit powerful flares that can "sterilise" lifeforms on nearby planets. Maybe microbial forms can protect themselves though?
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#226Earlier quoted context omitted.
Well, someone needs to treat the hydrogen sulphide with excess methanol over an aluminium oxide catalyst. I suppose a robot could do it... For a non-life explanation, you're really looking for something that could plausibly happen in (abiotic) nature, not an industrial process.
The only thing that could make a nerd happier than detecting alien life would be detecting alien robots.
Wait, what's the difference?
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#227Earlier quoted context omitted.
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…
no matter how advanced the civilization is, proxima centauri will always be 42 trillion kms away. Our civilization in current stage is not even close to 0.1% the speed of light but lets say your advanced civilization goes at 99% the speed of light, still doesnt change the fact they need 4.25 years approx to reach earth. Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot relia…
Where did you get the 1bn km number? I'm asking it seriously, I'd like to better understand how to calculate these things.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#228Some speculation On DMS: - DMS is a very specific configuration that’s rarely the endpoint of non-living chemical cycles. - The simplicity of DMS doesn’t make it less indicative of life—it actually makes it a very selective molecule, which only shows up in large quantities when life is involved (at least in Earth-like chemistry). - Until we find a compelling abiotic pathway, high DMS remains a strong biosignature, es…
Not that exciting until they find other different biomarkers. Dead Comets have DMS: https://arxiv.org/abs/2410.08724 And the interstellar medium.... "On the abiotic origin of dimethyl sulfide: discovery of DMS in the Interstellar Medium" - https://arxiv.org/abs/2501.08892 "...Although the chemistry of DMS beyond Earth is yet to be fully disclosed, this discovery provides conclusive observational evidence on its effic…
This planet is 2.6x larger than Earth and has concentrations of DMS "thousands of times stronger than the levels on Earth".
It would take a lot of cometary impacts to seed the entire ocean with that much.
From the paper [1]:
> Therefore, sustaining DMS and/or DMDS at over 10–1000 ppm concentrations in a steady state in the atmosphere of K2-18 b would be implausible without a significant biogenic flux. Moreover, the abiotic photochemical production of DMS in the above experiments requires an even greater abundance of H2S as the ultimate source of sulfur—a molecule that we do not detect
[1] https://iopscience.iop.org/article/10.3847/2041-8213/adc1c8/...
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#229This is happening 124 light years away from earth. That means if we develop a way to make a space ship accelerate at 1g for a long period of time, you could go there in just 10 relativistic years. Unfortunately, whilst science allows such a rocket, our engineering skills are far from being able to build one.
If you can somehow make a ship capable of constant acceleration at 1G, and had enough shielding on it to protect it against the radiation, you can travel to any point in the observable universe, in a human lifetime.
If you just keep accelerating and left as a 20 year old, you'd be in your 50s when you saw the final stars born and die in 100 trillion (earth) years time.
That's how crazy relativity and torchships are
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#230Earlier quoted context omitted.
Most of the sky is left unexplored. I think it’s premature to suggest we don’t see things. There are too many things to see in a single lifetime.
But if there was a Kardashev type III civilization in the Milky Way, they would have had full control of our entire galaxy in a mere 200 million years or so. And we can be pretty sure that such a civilization doesn't actually exist. Which suggests that either advanced life is rare, or dies off long before it ever reaches such technological breadth.
Maybe they have different motivations than humans because they are aliens.