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We May First Find Aliens on Eyeball Planets
- John_KZ 8y agoThat's a lot of assumptions based on top of other assumptions. All asserted as the truth. I'd be more willing to listen if the author was aware of this potential for error.
- nkozyra 8y agoThe argument seems to stand on the greater risk to life on a planet with relative axial rotation. So one without is more likely to have "sweet spots." As an earthling this is probably the first thing you think about when you read about Mars - too hot for life in the day, too cold for life at night. But that makes way too many assumptions relative to _human_ life. It assumes nothing could be rigid enough to adapt to day and night extremes greater than Earth's. It seems to me the greatest challenge to thinking about potential life outside this planet is being mentally bound to the constraints of life on this planet.
- jacquesm 8y agoLife on this planet doesn't seem all that constrained. There is life in the deepest spots in the ocean and in the highest reaches of the atmosphere and everywhere in between.
- pc86 8y agoI think the point is that when you move to an interstellar scale, the "extremes" on Earth are actually a very, very narrow band of possible environments. Even just within our solar system the differences in temperature alone are many orders of magnitude beyond those found on Earth. That's ignoring the differences in gravity, pressure, chemical makeup, etc. Disregarding the possibility of life elsewhere that couldn't possible survive on Earth discounts most of the planets we know about.
- jacquesm 8y agoThere are some relatively clear 'bands' where we expect life to be possible. Anywhere from -273 right up to 1,000 degrees Celcius. That's a 'narrow range' by the range available within the solar system but lower you won't go and higher has some interesting problems associated with stability of the vast majority of materials that could be your building blocks. Gravity and pressure are less of a consideration though those would 'shape' life much as life on earth has adapted to the pressure gradients available. Gravity is even less of a concern. Chemical makeup is important, it determines the available building blocks which is one reason we are concentrating on second generation stars because they have enough complex building materials lying around. First generation star systems are chemically too simple to support life as we can imagine it. So if survival of those life-forms depends on gravity, pressure or chemistry then we definitely should not rule out places where those are different than on earth, in fact that is to be expected. But temperature is a very important factor and the make-up of the star itself is also very important. So it makes sense to check the likely places first before spending time and effort on much more unlikely places.
- bluGill 8y agoI'd put the lower bound for life at closer to -100C, as you go below 0C there just isn't enough energy available for life.
- jacquesm 8y agoIt won't be fast, that's for sure!
- jakelazaroff 8y agoI was going to comment that I thought 100C was the upper bound for life that relies on water, since any higher than that and it boils (although in retrospect that only happens at standard pressure). But I googled a bit and found a BBC article on the Uzon caldera in Siberia [1], which hosts microbes that can thrive up to 122C! (1000C is still far out of reach, though). Some of these organisms also have novel ways of acquiring energy, so it seems like research like this is probably our best near bet for understanding how life can thrive in extreme conditions. [1] http://www.bbc.com/earth/story/20160209-this-is-how-to-survive-if-you-spend-your-life-in-boilin-water http://www.bbc.com/earth/story/20160209-this-is-how-to-survi...
- simias 8y ago>It seems to me the greatest challenge to thinking about potential life outside this planet is being mentally bound to the constraints of life on this planet. I always felt the same way about astronomers linking liquid water with life but then again where do you start if you don't use the only known instances of life in the universe as a template? Maybe it happens that there's a viable evolutionary path for sentient Nitrogen clouds but how would we know that? Furthermore it doesn't sound too absurd that the very complex chemical constructs necessary for life would have a greater chance to stabilize in less extreme environments with a smaller temperature amplitude. Especially if you're looking for complex life and not merely microbes (which tend to be a lot more resilient).
- ekianjo 8y agoThe rationale is because carbon chemistry is the richest chemistry out there. Other elements are not nearly as flexible to sustain complex molecules while maintaining the possibility of reversability in chemical reactions. Thats actually a very sound argument.
- bluGill 8y agoliquid water acts is a catalyst for a large number of chemical reactions. life on earth is complex in a way that only carbon base molecules with liquid water can support. Maybe life can exist where average temperatures are 90C (but this in itself changes the possible chemical reactions)
- scotty79 8y agoI always thought that most likely place to have life in solar system (except for Earth) is Venus. Also hardest to discover for us. Most likely because looking at extremophiles on Earth, you just need somewhat stable energy gradient and you'll find some life that draws energy from that gradient using weird chemistry. Hardest to find for us because most of our chemistry research is geared towards carbon compounds around 20deg C, not sulfur compounds around 500deg C that dissolve most of our equipment in minutes.
- jerf 8y ago"It seems to me the greatest challenge to thinking about potential life outside this planet is being mentally bound to the constraints of life on this planet." I'm having a hard time finding all the people stodgily insisting that only life exactly like Earth's is possible through the hordes of people screaming about how it might not be. Everybody already knows that life might not be exactly like Earth life. Any illusions to the contrary have been shattered by Earth life itself and the concrete existence of extremophiles, which are themselves already not what most people imagined "Earth life" to be.
- bluGill 8y agoI'll make that claim. Even extremophiles are very earth like life forms: the have similar chemistry behind them.
- simias 8y agoI tend to agree, however with the universe being so vast and the number of planets out there simply impossible to comprehend I always end up thinking "that sounds far-fetched but it almost certainly happens somewhere in the universe". Now of course if we consider the much, much smaller subset of planets we may hope to actually observe then of course it might not be so likely. I also think the initial point of the article in insightful, although rather obvious: since the planets we're currently looking for are not Earth-like (because we're currently unable to detect planets such as Earth in other solar systems) it means that if we find something it'll probably be very different than what we're used to. Now of course the author goes on to flip that around by saying "since we're looking for planets that are not like earth we're going to find this and that" which is obviously a bit presumptuous. Still, fantasizing about alien worlds is something I always greatly enjoy so I'll allow it.
- simonh 8y agoIs going for the jugular like that really fair? It's clearly speculative, but backed up worth reasoned argument. >That image may very well be completely off-base. There is good reason to think that the first potentially life-bearing worlds that are now being detected around other stars... "may be", "Good reason to think". Not exactly ex-cathedra pronouncements from on high.
- Cthulhu_ 8y agoDisregarding the matter of life and whatnot, it was interesting to read a piece on what the climate and behaviour of a planet like this would be. Not something I've seen in science fiction yet.
- prewett 8y agoThe closest I've come across is Kim Stanley Robinson's Blue Mars, which has a city on Mercury that rolls on rails along the terminator, pushed along by the thermal expansion of the rails behind it.
- chopin 8y agoThe article explains in length what Eyeball Planets are but gives little arguments why life should be more abundant there compared to other planets apart from a vague number argument.
- Tepix 8y agoHere are some reasons: Pro: - Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighbourhood of the Sun - Red dwarfs exist for a long time (longer than ten billion years) which gives life a long time to spring into existence (or start via panspermia) and evolve - Planets in the habitable zone of a red dwarf are tidally locked ("eyeball planets") due to their small distance to the star So there is very likely to be a huge number of these types of planets with stable conditions over a long period of time. Con: Flares by the red dwarfs (which are not so rare) could destroy life on these planets
- Klathmon 8y ago>Flares by the red dwarfs (which are not so rare) could destroy life on these planets As a layperson, I'm curious how "bad" those flares are. Is it in the realm of possibility that life that develops on these planets could "hide" from these flares when they happen, or evolve defenses against them for when they happen? Or is it more "turn the surface into lava" kinds of events?
- dak1 8y ago~100 times the intensity required to kill even the hardiest microorganisms, bad. https://phys.org/news/2018-04-proxima-centauri-flare-powerful-visible.html https://phys.org/news/2018-04-proxima-centauri-flare-powerfu...
- scarmig 8y agoIn the places that are exposed to the UV light. You could have life that's 100m deep underwater, or living in protected structures (caves, etc). Life could evolve more protections against UV (e.g. some kind of carapace that the organism resides within). Maybe the hard part is figuring out a way to use UV-heavy light to generate energy.
- nabla9 8y agoThe background for the article is 'tilt erosion time' and the large number of tidally locked planets in the habitable zones of numerous low-mass stars. Many new discovered planets are tidally locked: Kepler-438b, Kepler-442b, K2-3d, K2-155d. It was previously assumed that tidally locked planets would not be habitable. New climate modeling seems to change this view. No snowball on habitable tidally locked planets https://arxiv.org/abs/1705.08904 https://arxiv.org/abs/1705.08904 Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of Tidally Locked Planets https://arxiv.org/abs/1307.0515 https://arxiv.org/abs/1307.0515 Tidal obliquity evolution of potentially habitable planet s https://arxiv.org/pdf/1101.2156.pdf https://arxiv.org/pdf/1101.2156.pdf
- jerf 8y ago"New climate modeling seems to change this view." And this modeling was confirmed to be accurate... how, exactly? This strikes me as a classic case of goosing the model until it says what you want it to say, and then getting in the news. We have no reason to believe these models. We have no reason to believe prior models, either. We have no reason to have any confidence in our ability to model a tidally locked planet, of unknown and arbitrary chemistry, around an unknown star, for unknown periods of time, with unknown orbital characteristics across geological time, with zero data points. We particularly have no reason to believe in any estimates of how long such a system could last; it doesn't seem to do life much good if there's a place for it to exist for a couple of million years, followed by freezing. The simulation is almost certainly unstable here; very small changes in the stability of this configuration will have massive changes to the result over even a few million years. There's also more to life than just a comfortable temperature. Life is possible on Earth in part because we have a moon and plate tectonics keeping this stirred up, so some of our vital nutrients don't just sequester themselves somewhere chemically convenient after a couple of million years and then hang out there for the rest of the planet's existence. Do these types of planets have a solution for that? We have no idea. (One advantage of the Earthlike planets is that we do in fact have an idea... we know it's at least possible once.)
- nabla9 8y ago>We have no reason to believe these models .... What is your level of expertise or knowledge of planetary astrophysics and climate modeling?
- throwaway1982x 8y agoI find that it completely unlikely that 'eyeball' planets would have a life-supporting zone. Over geological time period, the zone is likely to suffer unpredictable and novel variability which is not conducive to developing life.
- send_computers 8y agoCan you elaborate there? This seems like a very speculative statement to conclude 'completely unlikely'.
- jameshart 8y agoGeological-timescale variability is VERY conducive to evolution.
- XorNot 8y agoWe also don't have timescales for abiogenesis in a sterile environment - i.e. given the right ingredients and energy input, no existing life forms...how long does life take to appear? There's no particular reason that timescale has to be very long - and we know life on earth got started pretty damn quick after the planet cooled off enough (EDIT: in the sense that the planet is ~4 billion years old, the earliest life is dated to 3.5 billion years old, so the number is somewhere between a little over 0 and 500 million years).
- rsynnott 8y ago> Over geological time period, the zone is likely to suffer unpredictable and novel variability Earth does that too, though. Ice ages, the odd large impact, etc.
- throwaway1982x 8y agoI meant far more frequently than on Earth, and far more extreme. "Life finds a way" - but if the temperature suddenly jumps 100 degrees because your goldilocks zone librated into the sun, then you ain't got much capacity to evolve protection from that.
- fiblye 8y agoThe most interesting thing that came to my mind reading this was how different life would be without any distinction between night and day. If the amount of sunlight reaching the planet were consistent at all times, would life (assuming it followed an evolutionary path like earth's) still evolve to have frequent sleep or rest periods?
- nnx 8y agoThis is so intriguing indeed. Maybe most creatures on such planets would evolve towards unihemispheric sleep, as some Earth species did (eg. dolphins). Unihemispheric slow-wave sleep (USWS) is sleep with one half of the brain while the other half remains alert. https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep
- eloff 8y agoI was wondering if such creatures would sleep at all with 24 hour daylight. They might evolve other mechanisms to get the same benefits.
- bluGill 8y agoLions sleep 22 hours/day, even though it is light during many of those hours. Light/dark is only one factor in sleep, there are others.
- felipeko 8y agoEvolution on earth is heavily influenced on dark/light cycles through its entire history. No evolutionary path that has received this influence can tell us anything about what would happen, on things that are highly correlated to it, for one that has never received this influence.
- bluGill 8y agoof course, but the reasons lions sleep far more than the day/night cycle requires are a factor that applies elsewhere, and thus might result in something similar.
- edoloughlin 8y agoSun in a fixed position in the sky, impassible ice and desert barriers on all 'sides'. These planets must be full of flat 'earthers'.
- some_account 8y agoTHIS planet is full of flat earthers. :)
- eloff 8y agoIt was anyway. Now they're a blessedly rare species.
- gregknicholson 8y agoFlat Earthers are an elaborate hoax ;)
- jakelazaroff 8y agoOn the other hand, it'd be far more straightforward to circumnavigate a planet like this since there's only one dimension in which you can travel!
- nafey 8y agoReminds me a lot of the world of One Piece manga
- progval 8y agoAnd cylinder 'earthers'!
- adrianmonk 8y agoTwo of their most memorable technological milestones might be: 1. First crossing of the hot side, passing through the point where "sun" is directly overhead. (Having the sun directly overhead would probably seem very profound and unusual to them.) 2. First crossing of the cold side, passing through the opposite point. Both would have unique challenges. Crossing the hot side would require an amazing ability to keep cool. You can keep warm by burning stuff and using lots of insulation, but how do you do the opposite? Crossing the cold side would have temperature challenges and also very difficult navigation because of the continuous darkness. Maybe there would be moon(s) and stars for some light, though. In both cases, I wouldn't be surprised if the first crossing had to wait until the invention of the airplane. You definitely aren't doing it by sea the first time like we did here on Earth.
- kensai 8y agoTrue thing. In "Another World" it looked totally different, both in fauna and flora.
- greggarious 8y agoThe article reminds me of another[1] HN article... this one says such a planet might be covered in oceans. I wonder what kind of life develops on an ocean planet? :) (This is all idle speculation but it's fun to think about) [1] "Group of scientists suggest that octopuses might actually be aliens " https://news.ycombinator.com/item?id=17110874 https://news.ycombinator.com/item?id=17110874
- madeuptempacct 8y agoGeorge RR Martin is crying over the missed opportunities for his series here.
- madeuptempacct 8y agoWould this eyeball planet structure affect geography? I.e. would the terrain be flatter? Would there be more or less volcanoes? No blanket statements could be made because it would depend more on composition?
- pulsarpietro 8y agoI would have added "maybe" at the end of the title :-)
- 3chelon 8y agoWhile I agree with most of the other comments that there's little evidence for the argument of the article, it is refreshing to see a different take on the whole "earth-like planets" topic. I am regularly shocked by how little imagination commentators in the popular science press seem to have on this subject. Even highly-respected scientists frequently refer to "requirements" for extra-terrestrial life such as carbon-based chemistry, the requirement for water, a mechanism of natural selection, etc, etc. (Actually I consider the last one, posited by Dawkins, to be probably the closest to the truth.) I guess it's simply the anthropic principle at work, but even the nature we see on our own planet far surpasses our imagination often (especially at the microbial level), so why should we be placing any constraints on the rest of the universe?
- XorNot 8y agoCarbon-based chemistry isn't the worst requirement to throw in there, since the only plausible analogue - silicon - for example doesn't form stable analogues of the usual amino acids at room-temperature. Now it would be reasonable to say "well what about extreme environments" but we are specifically looking for planets with temperatures and "ambient energies" similar to ours - so it's reasonable to think that whatever chemistry is there probably has to follow Earth to a large degree. If instead we were talking about high-pressure hot Jupiters or something, then it gets more interesting - but that's going to be something so different we're unlikely to recognize it at all (what consciousness does sentient life which evolved in a gas-environment have?)
- 3chelon 8y agoExactly. We think of things recognisable to us, in scale and environment, but as the article pointed out before it got too fanciful, it seems far more likely we'll find actual life by looking outside these constraints.
- mkirklions 8y agoWell carbon based compounds are significantly more stable when they grow in size than any other atom. That bond stability had to play a gigantic role over the last billion years of evolution.
- phaedrus 8y agoImagine if such a planet had a small residual rotation left - any civilization on it would be constantly rediscovering millennia-old sites as previously abandoned regions rotated back under the inhabitable region.
- SmallDeadGuy 8y agoReminds me of a writing prompt I saw a while ago [0]. [0] https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a_planet_rotates_once_every_1000_years_so_that/ https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a...
- NegativeLatency 8y agoAnd constantly scooting back into the warm side themselves.
- sli 8y agoIt'd be an interesting variation on being nomadic, where you would indeed migrate, but you'd stay in the same "logical" location on the planet. Basically, only migrating laterally, and only once every few thousand years or so.
- cwkoss 8y agoThis is a beautiful idea, would love to read a novel based on this premise. The sort of forced nomadism from "only" having ~1000 years before a location becomes uninhabitable would make for some interesting dynamics. Real estate at the leading edge would be very valuable, potentially with some kind of homesteading dynamic for claiming the land (as nobody has lived there for thousands of years). Also value of land would depreciate over time because it would have an 'expiration date'.
- logfromblammo 8y agoEventually, the surface-dwellers start to migrate into a region where a previous civilization went underground, and there is dramatic conflict as the nomads try to claim territory that the diggers never abandoned. Also, the polar territories would only have to worry about precession, and their land might have a longer expiration date.
- jobigoud 8y agoThere is a third option besides tidal lock and night/day cycle. Some moons in the outer Solar System have Chaotic Rotation[1]. These bodies don't have a fixed rotation axis or period. There could still be such a Moon orbiting a planet in the habitable zone, or even a small planet in a belt like structure orbiting close to a red dwarf. I wonder what lifeforms could evolve when the amount of light/energy received is unpredictable and varies constantly? [1] https://en.wikipedia.org/wiki/Chaotic_rotation https://en.wikipedia.org/wiki/Chaotic_rotation
- quantumhobbit 8y agoChaotic rotation occurs primarily in bodies that are not spherical. These tend to be smaller, because gravity forces larger bodies into spheres, and would have a thinner atmosphere if any due to the small gravity. Not saying life is impossible on such a moon, but it would be even weirder than just strange day night suggests.
- mkirklions 8y agoBut wont millions of years of chaotic rotation cause a large body to become round? Thousands of years this sounds realistic, but remember the scale of things is in billions of years.
- lainga 8y agoI believe the chaotic rotation would stop as soon as the body became round, to conserve angular momentum.
- deleted 8y ago[deleted]
- koonsolo 8y agoWow this brings back memories! When I was 18, a group of friends and me were going to create a computer game based on this tidally locked concept. The story went as follows: An explosion would occur in a huge spaceship close to such a planet. Both parts of this ship would make an emergency landing on this planet. One part on the cold ice side, one on the hot desert side. Both teams would work their way towards the habitable ring, in a true real-time-strategy (Command & Conquer) fashion. Needles to say, the game never went further than this concept phase. Although we did visit a small local game developer here in Belgium called Larian, to get a feel of running a game development company (must be back in 1998). Larian is now known for the critically acclaimed Divinity: Original Sin.
- progval 8y agoI like it! And you could make sequels where they each develop into a different civilization with different technologies.
- chefandy 8y agoMan, living on an eyeball planet sure would be convenient for producing solar energy.
- macintux 8y agoI wonder whether you'd ever achieve the level of technology required to take advantage of it, though. Mining would be brutally difficult outside the habitable zone.
- matte_black 8y agoIt has been said that the equators of eyeball planets are the most romantic places in the universe, as they are in a perpetual never ending sunset. Great place for a honeymoon.
- cwkoss 8y agoWould be interesting to see how a real estate market would develop on a planet like this. My guess: - Side of planet closest to sun would be great for solar, agriculture. - Equator would be great for retail, recreation - constant sunset makes everything look beautiful. - Just further than the equator might be an idea place for housing - it's always dark, but short commute to light. - Further away from the equator would be cold, which could be useful for heavy industry (particularly exothermic processes) I wonder how a society's 'clock' would work without the day/night cycle. Would people coalesce around a certain common "day" cycle or would everyone be on different schedules so society operates in shifts?
- scarmig 8y ago> Further away from the equator would be cold, which could be useful for heavy industry (particularly exothermic processes) Bitcoin mines! I wonder how much benefit, if any, data centers get from operating in colder regions.
- matte_black 8y agoIt’s clear that the equator would be the playgrounds of the rich, where grass is always green and the lighting always perfect. Properties facing the sunset would fetch a premium over those facing the dark empty sky. Going away from the center, properties would get cheaper due to harsher conditions, the poorest of people living in increasingly hotter and colder conditions. But they would also live closer to the factories that lie toward the poles of the planet, making for faster commutes. Somewhere in the very hottest and coldest extremes, would be a good place to keep prisons.
- cwkoss 8y agoIf enough capital is available, I'd expect the rich to grade the equator so it slopes towards the sun, allowing for more real estate to get sunny views.
- trhway 8y agoLife, at least it's origination, requires cycling - this is what allows for the original buildup and release of entropy gradients which follow spacetime trajectories different from the ones of the dead matter. For example you get cells (and especially precells) to get divided by temperature cycling.
- wainstead 8y agoA pretty good short story set on a tidally locked planet is "Weep For Day" by Indrapramit Das.
- samatman 8y agoIf only Hal Clement were around to write hard science fiction set on an eyeball planet...
- jaddood 8y agoThis kind of reminds me of Norwegian mythology where, as far as I can remember, there was an icy world in the North and a fire in the South, and as the fire melted the ice, a thin strip of life began forming.
- mrhappyunhappy 8y agoThis would make for a great blockbuster movie. Something mad max-esque
- 394852034 8y agoI'm sure that alien contact will go really well. Because nothing but good things can come of that, right? The state of willful self-delusion about reality among people is mind boggling to me. It's such a contradictory state that the most "educated" are also the most foolish at many times. In spite of all the calamities that are all caused by "experts" and the most "educated", no one ever seems to even question letting the most psychopathic of our species run things and make potentially and ever more existentially and terminally risky choices for everyone. As Stephen Hawking said in paraphrase, "You may not want to draw alien life to Earth by broadcasting our location into space". There is approaching zero chance that an advanced alien life form will in any way be as psychopathically altruistic as the current state of western liberal self-destructively suicidal types. It really won't matter when the mentally deranged have lured a pillaging alien life form to Earth, but what are the ethics of doing so while we still have time to prevent them from leading to the total erasure of humanity through the acts of an alien life form that does not care about humans?