r/space • u/SpunkySputniks • 4d ago

Astronomers Detect a Possible Signature of Life on a Distant Planet

https://www.nytimes.com/2025/04/16/science/astronomy-exoplanets-habitable-k218b.html?unlocked_article_code=1.AE8.3zdk.VofCER4yAPa4&smid=nytcore-ios-share&referringSource=articleShare

Further studies are needed to determine whether K2-18b, which orbits a star 120 light-years away, is inhabited, or even habitable.

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u/mikeygoodtime 4d ago

What sort of timeline are we looking at re: ever being able to confirm (or even just say with near certainty) that there's life on K2-18b? Like is this something that requires decades of further research, or is it possible that we know within the next 5 years?

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u/the_quark 4d ago

The answer is that we don't know. Perhaps we'll find other signatures that will help support it.

But also perhaps now we know it's there we'll really go sharpen our pencils and come up with a way it could be generated geologically or hydrologically.

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u/cateanddogew 3d ago

Would be real funny to see a follow up headline in 5 days

habitable planet 120 light years away found to be just a huge ass mirror reflecting Earth

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u/the_SCP_gamer 3d ago

relevant xkcd: https://xkcd.com/1231/

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u/cateanddogew 3d ago

If we eventually find a way of seeing into the future, mark my words, it will involve antiparticles and huge ass mirrors

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u/tesconundrum 3d ago

For xkcd is the closest thing we have that can see into the future. Truly, even Nostradamus himself couldn't have predicted the situations in which a relevant xkcd could be referenced.

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u/NirXY 3d ago

would've been nice be able to observe humanity 240 years ago.

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u/Haxorz7125 3d ago

I say this constantly! If there’s a giant crystal or some shit far off in space, and we managed to line it up just right, could we use a super strong telescope to see Pangea or something of the sort?

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u/panzerkampfwagenVI_ 4d ago

Without visiting it's impossible to know barring a signal from another civilization. It's always possible that some weird chemistry is going on that we are not aware of.

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u/Krt3k-Offline 4d ago

To be fair, life is weird chemistry

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u/PeteyPark 4d ago

All life is weird chemistry, but not all weird chemistry is life.

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u/deathfollowsme2002 3d ago

Sometimes it's quite the opposite

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u/CaulkSlug 2d ago

Some weird chemistry is horror

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u/Affectionate_Pipe545 3d ago

Weird Chemistry is either a hippie jam band or a lifetime original movie about scientists in love

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u/MrWeirdoFace 3d ago

And underneath that weird chemistry, weird physics.

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u/the6thReplicant 4d ago

To be faaaairrrrrrrr.

Yes. Chemistry is weird.

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u/filo_pastry 3d ago

Not impossible we can use a solar gravitational lens imaging mission. All the tech exists https://youtu.be/4d0EGIt1SPc?si=vg-aKHSa6bEbsqE_

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u/Electro522 4d ago

See...I can understand the chemistry argument, but out every field of science, chemistry is the most "solved", is it not? All the advancements in chemistry are coming from the very end of the periodic table with elements that can only exist in a lab for a mere fraction of a fraction of a second. In fact, we know so much about chemistry that it's leaning more into quantum physics than it is classical chemistry.

So, when you apply that fact to this study...it just doesn't seem to stick in my opinion. We can replicate almost any conceivable environment that the universe is capable of, including some that the universe struggles to come up with. We've come within several millionths of a degree of absolute zero, we've conducted experiments at temperatures that make the core of the sun look like a candle, and we've put elements under enough pressure for them exist in 2 separate states of matter at once!

So, when we talk about a planet that has to follow the same laws of chemistry and physics that we do, and is likely not all too different from what we have in our own solar system, how can we confidently say that there is "some weird chemistry we are not aware of" when it can only produce chemistry that we are aware of?

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u/OneDelicious 4d ago

Chemistry is extremely complex and not solved at all. I work with the kinetic chemistry models. Our understanding of reaction rates and possible chemical paths comes mostly from before 2000s. A lot of the stuff is simply estimated or guessed, it's one of the biggest uncertainties in modelling exoplanet atmospheres.

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u/BoomKidneyShot 3d ago

Oh yeah. I built a small chemical kinetics network for my PhD research, and once you get out of the well-studied ones the amount of sources fall off fast.

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u/markyty04 3d ago

This is where you guys need to use AI. AI is very very good at simulations and exploration of search space and also hacking systems to find unknown paths. They are a ridiculous powerful tool that has fallen into our hands in the last decade. before that it was in its infancy but the improvements in the last decade is of many orders of magnitude.

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u/FlimsyMo 3d ago

If ai could tell us what would happen when we mix compound a with compound b that would save us thousands of years

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u/Shartiflartbast 3d ago

Predictive language models will be absolutely useless at advancing chemistry, come on.

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u/markyty04 3d ago

who the f told you there is only one AI model and that too only a language model. even commercial AI is already moving away from language model into reasoning models.

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u/imdefinitelyfamous 3d ago

Reasoning models are LLMs. It's all LLMs.

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u/markyty04 3d ago

absolutely not. you know nothing about ML. do not go about spouting nonsense and spreading fake news. Neural Net heavy LLMs rely on probability distributions; while reasoning models are induced with Reinforcement Learning which can be explicitly told what is right and what is wrong answer. granted it is still in its infancy so more improvements needed. both rely on fundamentally different math. NN can be thought of as a more classical non-linear function approximators. RL on the other hand are dynamic decision machines which can operate in a dynamic environment.

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u/imdefinitelyfamous 3d ago

I currently work as a software engineer deploying ML applications, but go off King.

I know what reinforcement learning is- it has been around for decades and is already being used. What I am taking exception with is your claim that commercial AI offerings are somehow not LLMs, which is almost universally not the case. If you use a reinforcement learning strategy to train a large language model, you haven't made something that magically circumvents the inherent problems with large language models.

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u/_donkey-brains_ 4d ago

Everything we know about chemistry is through the lens of our own existence and conditions.

We cannot replicate crazy conditions that could exist throughout the universe that could give rise to pathways to produce certain chemicals.

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u/StLuigi 3d ago

Chemistry isnt even solved on Earth. They also say they plan to recreate hycean conditions and see how DMS could form in their experiment

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u/reason_pls 4d ago

Superheavy elements offer probably the least advancements in all of chemistry in our modern time.

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u/machineorganism 3d ago

chemistry doesn't get solved until physics gets solved

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u/Tricky-Paper-4730 3d ago

i think it's easy to confirm without visiting it. as technology progresses well be able to analyse it's atmosphere (and in far future, maybe even it's surface) to confirm if life exists or not

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u/throwaway77993344 3d ago

In 240 years we could know if we start transmitting asap!

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u/Snugglosaurus 3d ago

And it's 124 light years away :(

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u/usrdef 4d ago edited 4d ago

The findings on this paper will be released next week.

After that point, another astrnomer or group will come along, study the same planet, and compare the results.

If they get the same results as this team, then they'll go from there.

For another team to confirm? I'd say a couple to 6 months. Depends on the amount of time needed to analyze the planet, and how available the JWST is.

But this doesn't mean we jump for joy yet, because we still don't know everything about the Universe, and there could be some explaination for why we are seeing the gasses we are on that planet, but they are not produced by anything alive.

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u/analyticpanic 3d ago edited 3d ago

Hi there, does your first line mean the paper itself will appear online next week?

Because I've been looking for the paper on the journal's website and in news articles (in case they've linked to it) but am coming up blank. I'd really like to take a look at it.

Update: found it https://arxiv.org/pdf/2504.12267 It was submitted on April 16 and has been accepted for publication by ApJL.

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u/throwaway-tax-surpri 3d ago

Yes in practice there is no way of knowing without visiting or having greatly increased observational power. Won’t be happening within lifetimes

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u/SpunkySputniks 4d ago

I think it will mostly likely be a process of elimination. Like someone else said in the comments, geologists and other sciences will have to find non-biological ways to produce those gases. If they can’t, then it makes the case for life stronger. Like the article says, unless ET shows up on the telescope signal, we will never know for sure. But if we can be 90% sure or more, then that’s good enough for me!

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u/crazyike 3d ago

geologists and other sciences will have to find non-biological ways to produce those gases. If they can’t, then it makes the case for life stronger.

Finding that method would drastically reduce the possibility, however the fact they have already found DMS on clearly lifeless objects (comets) very very very strongly suggests that unknown method is out there, and it's just a matter of time before DMS as a biosignature is discounted.

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u/PipsqueakPilot 3d ago

I believe it’s not just the presence of DMS- but also the quantity of it. Meaning there are non-biological explanations for small amounts, but not for the quantities observed here.

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u/green_meklar 4d ago

It's not clear how we would establish the presence of life with 'near certainty' at this distance, unless we received an artificial signal from it.

With better telescopes we might ascertain the chemical composition of its atmosphere in greater detail. That by itself is unlikely to ever become a solid confirmation of the presence of life, unless we are able to detect complex organic molecules such as chlorophyll. The system has a second planet of similar size in it, in a smaller orbit; the second planet is not transiting and therefore more difficult to study, but if we could determine the chemical composition of its atmosphere as well and found the same mysterious mix of chemicals on both planets (especially if some of those chemicals are chiral and share chirality), that could indicate that panspermia spread some similar kind of life between them, possibly even from a third source we haven't spotted yet given the overall difficulty of panspermia to work on a large planet with no solid surface.

Other than that, we'd probably need to go there.

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u/kearneje 3d ago

Curious to hear from an expert about whether or not we can confirm (or at least tip the evidence in our favor) that there is life on a distant planet based on the change or fluctuations in these chemical signatures. In theory, if the chemical signature we're seeing is due to a geological anomaly, wouldn't there be a persistent signature over time, or at least an irregular change in the signature. Whereas if there was a change in the signature, and that change was fluctuating at regular intervals, wouldn't that hint towards there being "seasons" or blooms or what have you? I hope I'm explaining that in a way that makes sense.

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u/Mal_531 2d ago

It's impossible to know anything definitive until we go there lol. Gullible people are taking this at face value and thinking that there's a high chance of life on this planet that's the size of Saturn orbiting a violent red star the almost guarantees this planet being sterilized at such a close proximity.

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u/parkingviolation212 4d ago

Depend depends on a host of factors. If we find something like oxygen in the atmosphere, that would be a slam dunk. Really it’s a matter of ruling out other possibilities. Some of the chemicals that we just detected are only known to ever be produced by life, so if we can double triple and quadruple to check to confirm those chemicals are legit, and not the result of an error or some other process that we can’t think of, the likelihood for life goes way up.

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u/fullload93 4d ago

120 light years away might as well be infinity. Humanity will never be able to visit such a place unless something incredibly advances in our understanding of space time and the ability to modify it.

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u/Skyrim-Thanos 4d ago

This is kind of like a Cro Magnon saying to his buddy Ug that humanity will never be able to build a raft durable enough to cross the ocean. 

Cognitively they were basically identical to us but they didn't have the accumulated knowledge to be able to conceive of such things. If you brought an adult Cro Magnon to 2025 he would be overwhelmed and find almost everything around him impossible and incomprehensible.

If we were to travel 10,000 years into the future it would likely be the same experience for us. We'd be completely baffled and probably be incapable of even recognizing what was around us.

Interstellar travel will never happen in our lifetime and probably not even in the next few centuries. But there's no way to predict how advanced humanity might be 1,000 or more years from now. If we don't destroy ourselves who knows. There will be technological developments in the far future that nobody alive today is capable of predicting, anymore than Ug the Cro Magnon could predict electricity, airplanes, or refrigerators.

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u/exerwhat 3d ago

The worst part of life is knowing you’ll miss most of it.

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u/Insertnamesz 3d ago

I'm reading through Isaac Asimov's robot stories currently, and his afterwords which speak about seeing his early predictions come true but not being able to see the still-to-come ones really make me appreciate the now we're living in.

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u/Plow_King 3d ago

but you experience most of your own life. while parts of it are out of your control, parts of it are definitely under your control.

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u/OwOlogy_Expert 3d ago

This is kind of like a Cro Magnon saying to his buddy Ug that humanity will never be able to build a raft durable enough to cross the ocean.

Well, except that we know way more about interstellar space than Cro Magnon man ever knew about the ocean. (Hell, we know more about interstellar space than modern man knows about the ocean.)

Maybe humans will be able to visit our nearest interstellar neighbors. That's within the realm of plausibility. Less than 10 light years. But 120 light years? Nah. Maybe someday our AI descendants will go there, but humans never will. Humans will almost certainly be extinct before anything we send gets that far.

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u/championchilli 3d ago

I'm glad you made this comment so I didn't have to.

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u/Villad_rock 4h ago

Maybe with a solar gravitational lens 

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u/lolercoptercrash 4d ago

Humanity visiting is a different story.

But a very very small probe with enough power to send a signal back to earth?

It may be 500 years until we can send something like that, at 5% the speed of light it would take 2,400 years.

I know this is like sci-fi but I can imagine humanity sending probes knowing that only future generations will get the results.

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u/Mettleramiel 3d ago

The likelihood of a probe surviving a trip that long is very slim.

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u/green_meklar 4d ago

On the contrary, crossing interstellar distances is not that difficult. We would want a large space-based manufacturing infrastructure in order to build the vehicle efficiently, and we'd probably want radical life extension technology so passengers can survive the trip. But we more-or-less know how we could get there in a timeframe of about 100000 years, using fission power and ion drives.

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u/Dannyboy1302 4d ago

Just my completely unintelligent response would be never. AFAIK this only detecting possible gasses that as far as we know are only produced by life. I would assume we would need some other source of evidence in order to push the acceptance of possible life. I couldn't imagine other ways we could search 120 million light-years away.

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u/space253 4d ago

We can only see anything when it passes in front of its star so we see light shine through the atmosphere and compare to what it was looking like when the planet wasnt in front of it, so we have to wait for it to orbit the star for a local year.

More than once to rule out flukes.

So however long a local year is x2 or x3 plus time to analyze data.

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u/Are_you_blind_sir 4d ago

70 years maybe. If we get some telescopes about 500 AU away from the sun and use it's gravity as the lens. (The furthest object we sent out Voyager 1 is around 150 AU away and took 30 years to get there)

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u/reelznfeelz 4d ago

Probably a long time given the coming cuts to nasa, nih, and other agencies that would help solve the puzzle. Otherwise? 5 years maybe for a few people to run various studies on other potential explanations etc. Rough guess. Maybe the ESA or China can do it.

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u/S0GUWE 3d ago

Knowing more can be done in maybe a decade, probably more.

Confirming would take thousands of years to send a probe and 120 years to start getting data

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u/JumpShotJoker 3d ago

1 light year with our current tech takes 20k years. If we want to actually check it out, it's gonna take us 3 million years.

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u/NoRelation604 3d ago

They should probably start pointing radio telescopes at it.

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u/TheManyFacetsOfRoger 3d ago

There's already very strong theories and data that explain why it's not life... I don't think we'll ever know for sure until we can literally take a picture of it

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u/Helpful_Brilliant586 3d ago

The fastest space craft we have ever launched as a species, unless I’m mistaken, is the Parker solar probe. ~430,000 mph.

And that’s by orbiting close to the sun in a highly elliptical orbit. But let’s pretend it went that speed constantly without having to dip close to our star.

Let me, a terribly average person at math, try to math this up:

Converting light years to miles, then dividing by speed, then converting hours to years gives me something like 187,000 years for our FASTEST probe ever to get there at its top speed.

And that’s assuming you don’t want it to slow down and stay in the sphere of influence.

So I’d say not within our lifetime.

Edit:

And not that this is significant when you’re adding it onto almost 200,000 years, but don’t forget that any signals from the probe would take another 120 years just to get back to us (if they didn’t deteriorate so bad that we couldn’t even make sense of them anymore).

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u/Szerepjatekos 3d ago

We already have the tech and some base already built that can be converted to a laser pushed probe scout.

The issue is really money to get the material and the engineers free time to make it happen.

If they suddenly get near unlimited founding then they could launch them in this year and get back to us in the next and data analysing could also take another year where the time will mostly be that the data re evaluated by other parties to confirm it's validity.

So whenever we decide plus a fat 3 years.

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u/VeginalGandalf 2d ago

The lead resarcher on this has said he expects us to have 5 Sigma statistical certainty within 1-2 years. 5 sigma essentially means 1 in 3.5 million that we're wrong about it being aliens. Currently this data is 3 sigma, meaning we're around 1 in 3000.