[HN Gopher] Extreme supersonic winds measured on a planet outsid...
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Extreme supersonic winds measured on a planet outside our solar
system
Author : PaulHoule
Score : 83 points
Date : 2025-02-14 17:01 UTC (3 days ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| dp-hackernews wrote:
| What, in this context (and most likely all), does outside our
| solar system actually mean?
| PaulHoule wrote:
| Like 500 light years away, as opposed to 500 a.u.
| samplatt wrote:
| Some more context:
|
| Sun -> Pluto distance is average of 40a.u.
|
| 500a.u. is 0.0079 lightyears.
|
| Nearest star to us is ~4.5 Lightyears.
|
| This exoplanet is ~520 lightyears away.
| thrance wrote:
| It means a planet orbiting a different star than our Sun, aka
| an exoplanet.
| michaelhoney wrote:
| As with black holes, in my lifetime exoplanets have gone from
| being conjectural-but-likely to scientifically rich observable
| phenomena. I love it.
| Timwi wrote:
| I have memories of asking adults how many planets in the
| universe we know of at a time when the answer was 10 because we
| had just discovered the first exoplanet (and Pluto was still
| considered a planet) and laughing when they would give answers
| in the thousands or millions.
| ziofill wrote:
| Woah how's that even possible? How does the fluid pick up so much
| kinetic energy? I'm not saying they're wrong, I'm just
| fascinated.
| est wrote:
| I guess a gas giant means there's super strong electro-magnetic
| field.
| saagarjha wrote:
| Possibly solar radiation?
| pfdietz wrote:
| The gas is probably mostly hydrogen. Hydrogen accelerated
| through a thermal rocket can reach 10 km/s or more.
| perihelions wrote:
| It's twenty times closer to its star than the Earth; the
| intensity of its starlight is hundreds of times brighter. Hot
| enough (1,400 K) to melt gold.
|
| I don't understand the details, but in some sense it has to be
| an atmospheric heat engine between the day and night side of
| this planet. (Its rotation is tidally locked, so they are
| permanently distinct sides).
| Earw0rm wrote:
| Not an original thought, but I wonder if the answer - or part of
| it - to the Fermi paradox is that we don't know all the ways it's
| possible for a planet in the Goldilocks Zone to be otherwise
| hostile to life.
|
| Liquid water and.. chemistry leading to an ambient pH of 2 or 12.
| Liquid water and.. radiation environment such that proto-RNA
| strands get immediately smashed to bits by high-energy rays.
| Liquid water and.. bombardment every couple of million years with
| enormous asteroid. Liquid water and.. 1800mph super-hurricanes.
| etc.
| davedx wrote:
| But there are also 7500 _known_ exoplanets within a few tens of
| thousands of light years of Earth. There are almost certainly
| multiples more than that we cannot see.
|
| The "Goldilocks Zone" is also highly anthropomorphised: there
| are extremophiles that live in all sorts of crazy environments
| on Earth.
|
| I'm coming around to the Dark Forest theory, personally, as
| terrifying as it is.
| Earw0rm wrote:
| Extremophiles don't tend towards complexity, though.
|
| And if each common variable has, say, a 10% range in which
| complex life can occur, you don't need that many to start
| reducing probability a lot.
|
| - Orbital stability? - Tidal and seasonal ranges? - Magnetic
| fields?
|
| - And the big one - properties of our Sun & solar system that
| make it different to others of a similar age? For example,
| are there galactic-scale properties that affect the surface
| environment of planets on a long enough time-scale, so that,
| just as Earth exists in the habitable zone of our Solar
| System, there is a relatively narrow galactic habitable zone?
|
| All the more reason though to get some telescopes built that
| can glean more detailed information on exoplanets. We might
| be in for another shock like the Mariner probes, or it might
| be 180 degrees the opposite.
| ZaoLahma wrote:
| > I'm coming around to the Dark Forest theory, personally, as
| terrifying as it is.
|
| If you're silent with the intent of remaining hidden, then
| that behavior must have been learned. Either you evolved from
| a prey type of species, or a non-apex predator.
|
| It would be strange of humanity is the only apex-ish predator
| intelligent-ish life form in the universe that blasts signals
| into space without consideration of who might hear them.
| PaulHoule wrote:
| We don't have telescopes capable of receiving accidental
| emissions from Earth (say television) at interstellar
| distances. It seems reasonable that you could use the
| gravitational lens of a star to do so if you could launch a
| probe to 800 au for each and every star system you want to
| monitor.
|
| As we transition to digital technology, our transmissions
| look more like broadband noise as opposed to having a
| strong carrier wave, cellular communications in 2025 are
| far less visible than, say, television broadcasts of 1975.
|
| Deliberate attempts to communicate with other intelligent
| life are quite forlorn. This message was sent to a globular
| cluster 25,000 light years away
|
| https://en.wikipedia.org/wiki/Arecibo_message
|
| There a few 100,000 stars there, somebody there would have
| to be looking at our sun in particular at the right time,
| then it would take at least 25,000 years to get a message
| back to us, in which case it is likely that we'll be
| extinct, collapsed back to hunter-gatherers, or maybe
| advanced but forgotten that we sent the message or don't
| care anymore.
| Etherlord87 wrote:
| > If you're silent with the intent of remaining hidden,
| then that behavior must have been learned. Either you
| evolved from a prey type of species, or a non-apex
| predator.
|
| Or you learned it in a non-evolutionary way, through
| logical reasoning.
| asdff wrote:
| No it is not necesarily learned. Even among species on
| earth a lot of behaviors are not learned but inherent. In
| other words, selection acts on a spectrum of behaviors and
| those with some fitness advantage you are likely to see
| more frequently in the next generation of offspring,
| extending until lineages of that offspring with that
| behavior are potentially all there is.
|
| A dark forest planet need not learn to be a dark forest
| planet in the same way an earth colored beetle need not
| learn to perfectly mask itself against the dirt from a
| bird; the fitter mutation given the context of the
| environment won out.
| thrance wrote:
| IMO the dark forest hypothesis leads to fun books but makes
| little sense. If a civilization is capable of the
| unimaginable feat of interstellar travel, surely their basic
| needs are well met and they aren't driven by base animal
| instincts anymore. They can probably engineer their own
| psyche. We humans will soon hit a population peak too, no
| exponental growth on the horizon.
|
| Also, I don't think the timescales make sense at all. It took
| 200 years for industrial civilization to develop, maybe 200
| more for us to travel the stars, but it takes billions of
| years for intelligent life to develop. I don't think there
| could ever be two comparable civilizations emerging at the
| same time, close enough to one another to compete for
| resources. Either the aliens found Earth millions of years
| ago and prevent us from ever existing, or there aren't any
| aliens closeby.
|
| If you want an optimistic outlook on the far future which I
| think more plausible, read "Diaspora" by Greg Egan.
| roenxi wrote:
| > If a civilization is capable of the unimaginable feat of
| interstellar travel, surely their basic needs are well met
| and they aren't driven by base animal instincts anymore.
|
| That is a bit like saying a human isn't driven by base
| instincts because we are so large and advanced compared to
| amoeba. We have concerns and options that are so far beyond
| the amoeba's comprehension that it makes no sense to even
| talk about an amoeba comprehending. And yet we are still
| driven by the same basic resource-acquisition logic as any
| microbe. Being more advanced again is unlikely to change
| that.
|
| Although I do agree that the Dark Forest hypothesis seems
| unlikely. It seems more reasonable to suggest that gravity
| wells and interstellar distances are a barrier that cannot
| be economically overcome, so intelligent life is bound to
| its own rock and eventually dies there. Then the odds just
| favour us not detecting life out there in whatever time
| period we've been looking.
| PaulHoule wrote:
| There's the question of motivation. It seems possible that
| an advanced civilization could gravitationally disrupt a
| small planet like mercury, turn it into solar collectors
| and particle accelerators and create multiple-ton
| quantities of antimatter and use that for interstellar
| travel, but they would likely choose to do something else
| with those resources.
|
| People have a hard time thinking on a timescale of half a
| lifetime, never mind a lifetime or several lifetimes. The
| realistic version of the Bussard ramjet is not that you aim
| for c=0.1 or more, but rather with D-D fusion you can make
| hops of 1,000-10,000 au to Oort cloud bodies, you could
| possible gravitationally disrupt an object like Pluto and
| turn it into little ringworlds or other colonies. It might
| take people like that 10,000 years to make it to the next
| star but if they can make a comfortable lifestyle along the
| way why would they bother? And why would we even care
| enough to send them out on such a quest?
|
| Even colonizing Mars is problematic in the sense that it's
| inconceivable that you could bring anything back from Mars
| that would give us flatlanders any economic incentive to do
| it. It might be a gift to a population of a billion or so
| people that will live there, but profitable to us? No way.
|
| So even if you could colonize the galaxy with Von Neuman
| probes, it won't happen in your lifetime, your children's
| lifetime, etc. Our civilization might not be there to get
| the data from the first probes to reach other stars and the
| more steps removed the more the probability drops. Still
| there's just that tiny probability of a 'dark forest'
| scenario where somebody finds one of those things and
| decides to do something about it.
| asdff wrote:
| That is if you assume the aliens will board a ship with
| conventional forces and enact a human style invasion.
|
| Now what if the alien was not even sentient. A giant
| configuration of some structure of chemistry just floating
| through interstellar space, catalyzing reactions when
| inputs are met, lying in wait otherwise. It might not "die"
| in the sense that any other mass of atoms doesn't "die."
| When faced with some input it might swell up in size,
| divide and diffuse elsewhere. Akin more to a random
| chemical interaction among a few molecules in pure solvent
| than life as we know it.
|
| Chemical structures like this could potentially be the
| wildfire patrolling the universe for fuel vs some
| spacefaring roman empire.
| thrance wrote:
| One might argue encountering something like this would be
| more akin to a natural catastrophe (like a killer meteor)
| rather than an alien invasion.
|
| Stephen Baxter wrote a novel in which galaxies would be
| regularly wiped out by a natural phenomena, and that
| explains why there are no aliens in his universe. It's
| "Manifold: Space" if you're interested.
| RandomBacon wrote:
| > I'm coming around to the Dark Forest theory, personally, as
| terrifying as it is.
|
| Perhaps it's just that advanced technology is extremely rare
| given another comment's supposition that there could be other
| intelligent life, just unable to make advanced technology, or
| along those lines: if they have the appendages to do so,
| maybe their environment doesn't have the resources.
|
| If you couple the above with the idea that FTL
| communication/travel is difficult or impossible, then it
| could take a long time for us to find evidence, and maybe by
| then we'll be extinct due to natural causes or devices of our
| own.
|
| Or maybe there's some theistic evolution component and we are
| the only species in the universe with divine providence.
|
| It seems to me that it would be impossible to prove or
| disprove any of those possibilities unless we actually
| discover extraterrestrial advanced intelligent life.
|
| (And even then, who is to say that God didn't create Edens on
| other worlds? So meeting aliens still might not disprove any
| divinity.)
| philipov wrote:
| A really simple answer to the Fermi paradox is that we're
| the first, or in the first wave, of intelligent species,
| and it's just too early for the light from the others to
| have reached us yet. We're not just looking into the
| distance, we're also looking into the past. Life is less
| likely the farther we look.
|
| It took a long time for the universe to create the
| conditions for a solar system like ours to exist in the
| first place, and why would have this happened so much
| faster elsewhere? The trend towards higher
| entropy/complexity is like a universal clock.
|
| The universe might look big, but our view of it is not
| homogeneous. We wouldn't even see ourselves if we tried to
| find us, unless we were a close neighbor.
| semi-extrinsic wrote:
| > the idea that FTL communication/travel is difficult or
| impossible
|
| Not just FTL. My hypothesis is that any type of substantial
| interstellar travel is going to be so enormously expensive,
| complicated and time consuming, an advanced civilisation
| will only do it once in a billion years. In the form of
| mass exodus when there are no more habitable planets in
| their system or their star is going nova. As this never
| gives exponential growth, it is enough to resolve the Fermi
| paradox.
| dbspin wrote:
| But that's simply not the case. We likely very close to
| the technology needed to get tiny objects to a decent
| fraction of lightspeed using laser arrays. Assuming
| genuine AGI is possible and miniaturisation continues,
| there's no physical reason a digital intelligence
| couldn't rapidly (on interstellar time scales) colonise
| the galaxy.
|
| Source - https://breakthroughinitiatives.org/initiative/3
| chasil wrote:
| The oxygen in our atmosphere has been prominent for millions
| of years, highly visible.
|
| Anyone who is curious is already here, or has been here.
| aithrowawaycomm wrote:
| The Fermi paradox seems to take for granted that complex
| multicellular life will eventually develop technological
| civilization, but there is no reason for that to be true. Orcas
| could very well be more intelligent than humans, but they are
| physiologically incapable of building tools. Human hands and
| visual processing were an evolutionary fluke that took tens of
| millions of years of natural selection, long before apes
| started using these adaptations to build simple tools. It is
| plausible that "bipeds with hands" will eventually lead to
| civilization: getting there is the hard part.
|
| Put another way: birds are very intelligent bipeds, but I am
| not convinced that the dinosaurs would have developed advanced
| technology if the meteor didn't hit. There has to be an
| evolutionary path to develop something like hands, which means
| either sprouting extra arms or compromising a claw / leg /
| wing. Perhaps that path shows up, perhaps it doesn't - maybe
| there are fossils of raptor-like dinos with unusually dextrous
| claws. But without hands, even superintelligent animals cannot
| reliably make fire, build ropes, sew leather, carve stone, etc
| etc.
| pc86 wrote:
| I've often thought about how likely it is there are
| intelligent and sentient civilizations that are content to
| their planet, or bounded to it by - as you mentioned -
| physiological constraints. I never connected that to "you
| probably need hands or something very closely approximating a
| hand" but it makes perfect sense.
| asdff wrote:
| Intelligence is such a bewildering fixation too when you
| think about it for ourselves. Due to science fiction
| writers and our insistence on anthropomorphisation we
| assume we will be forming treaties aboard an alien ship
| meanwhile we have yet to communicate let alone form a
| treaty with any other form of life just here on earth. The
| hubris is massive and it invades even the scientific
| community to a degree. Whoever put that human pictograph on
| voyager evidently did not consult an evolutionary biologist
| nor a statistician, probably watched an episode of Star
| Trek.
| sightbroke wrote:
| Hands, or tentacles, or a really long snout. There appear
| to be a variety of appendages that can be rather good at
| manipulating the environment for the users purpose.
|
| Forgot also swarms of many cooperativing organisms. Ants
| appear quite adapt at manipulating things to a degree.
| Teever wrote:
| Maybe Earth is rare in that most life evolved in a way that
| locks in morphology.
|
| It's entirely possible that it's far more common place for
| intelligent life to evolve in a way that allows that
| intelligence to direct the growth of an arbitrary body shape
| to solve arbitrary tasks.
| anjel wrote:
| Pterodactyls when on the ground are believed to have been
| quadripeds that walked on "hands" with finger-like
| appendages[0] hence the "Dactyl" part of its species-name.
| They perished agter the meteor. More up-to-date, I believe
| Bats have a similar skeletal feature in their design.
| Cetaceans have finger-like skeletal features in their
| flippers.[1]
|
| [0] https://duckduckgo.com/?q=pterodactll+walking+&t=newext&a
| tb=...
|
| [1]https://duckduckgo.com/?q=whales+used+to+have+hands&t=newe
| xt...
| jajko wrote:
| Things can hide in bigger depths with little to worry how
| surface of some massive ocean behaves.
|
| There are proper life filters but this isnt one of them. Folks
| just have to stop looking at survival and evolution in terms of
| 'if we dont have this pleasant spring stable situation life is
| doomed and has no chance'.
|
| Challenge breeds adaptation, thats how our ancestors made it,
| environment was brutal and extremely hostile. Didnt matter, not
| for us at least.
| est wrote:
| > WASP-127b, a giant gas planet located more than 500 light-years
| from Earth.
|
| How do you define "sound speed" on a gas giant?
| saagarjha wrote:
| You can simulate the speed of sound based on atmospheric makeup
| and temperature. That said, 9 km/s is probably going to be
| supersonic in most media (for reference, the speed of sound in
| most _metals_ is several km /s).
| tenpies wrote:
| As a layperson I thought that was odd choice too and would be
| an Earth-centric measurement, but the paper on which this
| article is based references this paper:
| https://iopscience.iop.org/article/10.3847/1538-3881/ac51d2
|
| Where they spell out a formula for the speed of sound in this
| type of planet given some assumptions. It's beyond my
| understanding, but I thought it was pretty cool. Section 4.4 if
| you want to have a look.
|
| Then back to the article paper:
| https://www.aanda.org/articles/aa/full_html/2025/01/aa50438-...
|
| > Using their formula we obtain sound speeds of the order of 3
| km s-1 for WASP-127 b.
| kjs3 wrote:
| Very cool! Isn't it amazing what happens when you don't
| assume bad faith or incompetence on the part of the
| researchers? You have to like a paper that has a section
| discussing the precipitation of vaporized iron out of a
| planets atmosphere...mindblowing. Of course, that means doing
| a little homework to actually understand what they already
| know and avoiding the lazy "me and my preconceived notions
| and lack of domain knowledge are here to tell you why your
| wrong".
| messe wrote:
| Wow, that's 9km/s. In comparison, objects in Low Earth Orbit
| travel around 8km/s.
| verisimi wrote:
| > Reaching speeds up to 33,000 km/h, the winds make up the
| fastest jet stream of its kind ever measured on a planet.
|
| Great planet for sailing!
| metalman wrote:
| there is a good chance that the "measurement" is recording some
| other phenominon, as this can only be an interpretation of albedo
| changes, and could be the signal from say, low orbiting small
| moons or a planetary ring,atmospheric electrical discharges in
| any case, it is most definitly not an actual wind speed
| measurement, plus strictly speaking "wind" can only happen in
| air, and this, again, can only be something else, with the use of
| the term "supersonic" not even remotly applicable, unless of
| course its of the football field per second type of calculation
| standard
| ridgeguy wrote:
| This isn't measurement of albedo changes. It's measurements of
| spectra that exhibit Doppler effect, which permits measurement
| of wind velocity. From the abstract:
|
| "We studied the transmission spectrum of the hot Jupiter
| WASP-127 b during one transit in the K band with CRIRES+."
|
| They acquired spectra for H2O and CO with hi-res transmission
| spectroscopy as the planet transited its star.
|
| https://www.aanda.org/articles/aa/full_html/2025/01/aa50438-...
| sinuhe69 wrote:
| Are not super storms raging for hundreds of years on Jupiter?
| What we can observe from earth are mostly giant exoplanets, not
| unlike Jupiter. Thus, I expect "normal" exoplanets are more like
| Mars and Venus. And who know, some could be very much earth-like!
| krick wrote:
| I don't understand. How can wind be supersonic? Isn't wind
| essentially a super-low frequency sound? Well, ok, not exactly,
| but still, it moves pretty much like sound. For it to be
| supersonic, air mass behind needs to move faster, than air mass
| in the front of it can be pushed, which seems kinda self-
| inconsistent. It doesn't make any sense.
| Evidlo wrote:
| The speed of sound on earth at sea level
| octubre wrote:
| I think wind is not like a sound, it's the bulk movement of the
| air itself instead of the propagation of a pressure wave (where
| there could be no average bulk movement). That's why wind can
| be different speeds and sounds are always the same speed (in
| the same air...)
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