[HN Gopher] Evidence of controversial Planet 9 uncovered in sky ...
___________________________________________________________________
Evidence of controversial Planet 9 uncovered in sky surveys taken
23 years apart
Author : spchampion2
Score : 140 points
Date : 2025-05-02 21:13 UTC (2 days ago)
(HTM) web link (www.space.com)
(TXT) w3m dump (www.space.com)
| bikenaga wrote:
| Original paper: https://arxiv.org/pdf/2504.17288
| codethief wrote:
| Non-PDF link: https://arxiv.org/abs/2504.17288
| DiogenesKynikos wrote:
| They forgot to change the title from "Overleaf Example" in
| their LaTeX source file.
| perihelions wrote:
| It's "hello, world!" planetary science with "hello, world!"
| tooling!
| metalman wrote:
| we already have a 9'th planet, but due to the greatest pedantic
| campain of all time, pluto got demoted. Though given the current
| situation, ha!, that could change.....perhaps the naming commity
| will get noticed, and be offered a chance to do a deal, and Make
| Pluto A Planet Again,(MPAPA)
| chess_buster wrote:
| Pluto for planet! https://www.planetarium-hamburg.de/en/pluto-
| for-planet
| rini17 wrote:
| The same happened to Ceres first. To be fair, Make Ceres A
| Planet Again!
| metalman wrote:
| Ya, I know but Ceres is going to get pushed into an
| intersection with Mars to generate an atmosphere and a
| hydrological cycle .......testing on fusion rocket drives is
| ongoing https://newatlas.com/space/pulsar-fusion-rocket-
| design-slash...
| QuadmasterXLII wrote:
| I mean, if you're pushing ceres around, teller and ulam
| already designed the ideal fusion rocket
| Qem wrote:
| Hopefully the energy released would also remelt it and
| restart it's magnetic field, to avoid volatile loss again.
| juped wrote:
| Yes, Pluto is the tenth planet.
|
| To discover Planet 9, simply open your ephemerides and look
| for "Neptune".
| db48x wrote:
| Back in the day Mercury, Venus, Earth, Ceres, Pallas,
| Vesta, Juno, Mars, Jupiter, Saturn, Uranus, and Neptune
| were the 12 planets. You could kinda consider Pluto to be
| the 13th planet, but in 1930 when it was discovered there
| were already over 1000 named asteroids. So Pluto is the
| 1146th planet.
| echelon wrote:
| If planets are required to clear their orbits, what was
| Jupiter called while the solar system was forming? A dwarf
| planet? A proto planet? The entire time?
|
| Was earth not a planet shortly before and after collision
| with Theia?
|
| The naming pedantry seems ridiculous given that we have such
| a small sample size.
| anton-c wrote:
| I find that to be the most weird one too. I don't know much
| about orbital mechanics but in the unlikely chance 2 bodies
| shared an orbit does that mean they aren't planets then?
| How close can two planets be before losing that
| designation? I share your ire.
| stouset wrote:
| Every single definition that segments a real world set of
| continuous objects into discrete buckets has surprising
| edge cases. This is basically inescapable.
|
| To steal a quote: All definitions are wrong. Some are
| useful.
| brookst wrote:
| This is especially important if it turnes out there is a black
| hole acting as an additional planet, since it justifies the
| "Planet X" name.
| rollcat wrote:
| The definition is pretty arbitrary. It's more interesting, what
| can we learn by studying that object. Even the trivia, like
| tidal locking, it was one of my 10000 moments
| (https://xkcd.com/1053/).
| gus_massa wrote:
| If you add Pluto, you must add also Eris and a few more, like 5
| or more, and perhaps also Ceres.
|
| Here is a nice graphic that excludes Ceres
| https://en.m.wikipedia.org/wiki/Dwarf_planet#Population_of_d...
| ryao wrote:
| We should add those planets to the official list too. Gauss
| considered Ceres to be a planet and I believe him over living
| astronomers.
|
| The motivation for this dwarf planet nonsense was to try to
| keep the official planet list small so children could
| memorize them with ease, but that is absurd. We do not remove
| countries from the map to make it easier for children to
| learn geography and there are over 100 of them.
| nonethewiser wrote:
| I mean... there has to be more to it than that right? But
| im also open to being red pilled on pluto.
| db48x wrote:
| For a generation, schoolchildren everywhere memorized the
| names of the 12 planets: Mercury, Venus, Earth, Ceres,
| Pallas, Vesta, Juno, Mars, Jupiter, Saturn, Uranus, and
| Neptune.
|
| The list was stable at 12 for about 40 years, but started
| growing again in the middle of the century. By 1868 there
| were 100 named asteroids. Not a single one has people
| living on it, so making children memorize their names was
| seen as a waste of time. Teach them about the asteroid belt
| and then move on to more important things. Likewise with
| the TNO: teach them about the Kuiper belt and the Oort
| cloud and then move on to more important things. No need to
| make them memorize Pluto, Haumea, Makemake, Gonggong,
| Quaoar, Sedna, and Orcus, nor any of the hundreds of other
| named TNO.
| irrational wrote:
| I would add those to the list of official planets, yes. Don't
| remove Pluto, add the rest.
| ta1243 wrote:
| So that makes Pluto the 10th planet an Neptune the 9th
| planet.
| randomtoast wrote:
| I find one theory regarding Planet 9 especially interesting, and
| that is that it could be a primordial black hole with a
| Schwarzschild radius on the order of just a few centimeters. So
| basically, just a golf ball-sized black hole. This would explain
| why we can see the gravitational effects on the other objects as
| described in many papers, and it would also explain at the same
| time why we have no direct observation of this object, because
| it's simply too tiny and black.
| api wrote:
| I really hope this is true, because it would mean there is a
| black hole close enough it could be examined and studied. This
| might allow us to test physics ideas that can't be tested any
| other way, and maybe even to "finish" physics.
|
| It could also allow gravity and Oberth effect acceleration of
| small probes to meaningful fractions of the speed of light for
| interstellar flyby missions. Imagine the Oberth effect boost
| from thrusting in such a deep gravity well.
| TheOtherHobbes wrote:
| I really hope it isn't true because if there's one out there,
| there will be others, and I'd rather not meet one in person.
|
| We don't have enough data to see whether there are unexpected
| instabilities in detected planetary systems. But it would be
| an interesting project to look for those.
| api wrote:
| They're not dangerous unless you get too close. A black
| hole is not a cosmic vacuum cleaner.
|
| If the Moon were suddenly transformed into a tiny black
| hole with the same mass, it would continue to orbit the
| Earth at the same distance. Ocean tides due to its gravity
| would continue normally. There would not be much effect
| except that it would no longer be visible with the naked
| eye and would no longer reflect the sun's light back to
| Earth. If you found it in a telescope, you might see
| gravitational lensing as it passed in front of the star
| field. Objects like probes or old spacecraft stages
| orbiting the Moon would continue to do so.
|
| The only danger would be that if things fell into it I
| suppose you might get dangerous X-ray and gamma ray
| emissions from its accretion disc that would be a problem
| at such a close range. That would not be an issue with a
| primordial black hole much further away.
|
| If there were such an object we could send probes to orbit
| it and study it, and some experiments may involve firing
| objects or shooting lasers or beams of particles into it to
| attempt to learn about the quantum effects at the event
| horizon. This could be massive for physics, allowing us to
| access and observe conditions and energies not replicable
| here on Earth with any current technology.
|
| BTW we don't have any hard evidence that primordial black
| holes exist, but many theories predict them. So far such
| predictions around black holes have a pretty good track
| record. If you made me bet, I would bet on them existing.
| They are a candidate for some or perhaps even all of dark
| matter, though even if that's not the case they might still
| exist. It's possible that the dark matter haloes we can
| spot with gravitational lensing are clouds of these things.
| ("Clouds" of course is a misnomer-- the distance between
| them would be many light years.)
|
| If planet nine is a PBH it means that at some point one was
| captured by our solar system into a Kuiper Belt orbit. Even
| if planet nine isn't one, there still may be small asteroid
| mass PBHs in our solar system, so we still might find one.
| They would require extremely sensitive X-ray or gamma ray
| telescopes or highly accurate gravitational models of the
| solar system to detect.
| nonethewiser wrote:
| That is very interesting and made me realize I did think
| of black holes as "sucking" things in. Which I see is not
| the right way to think about it.
| api wrote:
| It's an object with theoretical maximum density. That's
| one way to think about it.
|
| Another visualization: if you had an Earth mass black
| hole with a solid shell surrounding it at the same radius
| as the Earth's surface is from its core, gravity atop
| that shell would be 1g. The actual black hole would be
| about the size of a marble.
|
| If you got close to it you would of course be subject to
| insane gravity and be "spaghettified" etc. All the mass
| would be in that marble. But at a distance it would be
| the same.
|
| Compared to that object the Earth is mostly empty space.
| Ordinary matter is not that dense.
|
| Black holes are totally fascinating. They are in some
| ways the most extreme objects that can possibly exist. If
| we could study one we could learn a lot.
| philipov wrote:
| That's Newton's Shell Theorem for you.
| baxtr wrote:
| I love HN for these kind of comments
| XorNot wrote:
| They're also interestingly one of the most boring: every
| black hole can be described by 3 numbers: mass, spin and
| charge.
|
| Which is to say they are extremely high entropy.
| shiandow wrote:
| Running into a rogue black hole must be far less likely
| than an extinction level impact with a relstively boring
| big rock.
| ednite wrote:
| Honestly, if there is a golf ball-sized black hole out there
| chilling in the outer solar system, I'm all in.
|
| Let's fire up a replica of TARS, load up ChatGPT inside
| (TARS-GPT, patent pending), and yeet it straight toward the
| Schwarzschild golf ball. It'll narrate live.
|
| Imagine the livestream:
|
| "Approaching event horizon. Spaghettification at 3%. Mood:
| stretchy."
|
| "Entering gravitational lensing zone... wow, even my tokens
| are redshifting."
|
| Bonus: With the right timing and Oberth maneuver, TARS-GPT
| might sling itself into Alpha Centauri before we finish
| arguing whether Pluto's a planet again.
|
| Worst case: we lose a robot. Best case: we unlock quantum
| gravity and get a podcast from inside a black hole.
|
| I'd call that a win.
| ednite wrote:
| Not sure why the downvotes--if I came off wrong, my
| apologies. I genuinely meant it in a humoristic way. I'd
| honestly love to see a probe launched into a black hole.
| misnome wrote:
| It's the AI Poe's law: Any joke is indistinguishable from
| insane stuff LLM advocates will earnestly say they can
| do.
| kiba wrote:
| We could use the black hole to power our civilization due to
| how efficient it is for generating power.
| api wrote:
| Not at that distance but black hole starship drives are
| _theoretically_ possible. Far, far beyond our capabilities
| but possible within known physics. This is like Kardashev
| type II civilization stuff.
|
| Domesticating fusion would be much easier. That is within
| sight.
| ta1243 wrote:
| No need for something that exotic. The Earth alone receives
| more energy from the sun every hour than mankind uses each
| year.
| john2x wrote:
| Yeah but you can't raise trillions of dollars with that.
| Investors want to be able to tell to their friends at
| parties that they helped made blackhole tech possible.
| zveyaeyv3sfye wrote:
| Not sure I want a black hole in my backyard ;-)
|
| For all it's worth, there's no need to go black hole to
| explain the lack of visual observation. Objects that far from
| a star reflect very little if any light and would appear
| black to a black background.
| margalabargala wrote:
| Black holes are no more "dangerous" than other objects of
| equal mass.
|
| If a black hole with a mass of, say, Ceres hit the Earth,
| it would not be particularly worse than if Ceres hit the
| Earth.
| devoutsalsa wrote:
| I'd love see a mini-Ceres about this streaming on Nebula.
| magicalist wrote:
| > _If a black hole with a mass of, say, Ceres hit the
| Earth, it would not be particularly worse than if Ceres
| hit the Earth._
|
| This equivalency is true for many aspects of orbital
| mechanics (depending on setup giving sufficient
| distance), but I don't believe that's true at all for a
| collision. Someone with more knowledge correct me, but a
| black hole with the mass of Ceres would be _very_ tiny
| but also emitting a ton of radiation. The collision would
| be very different.
| margalabargala wrote:
| I more mean that the resulting moon-sized fragments of
| what used to be the earth would be equally devoid of
| life. I agree the physics might vary somewhat.
|
| If the black hole had a mass more similar to a 0.5-mile
| asteroid...well, I'm not sure what would happen. Would it
| just punch a hole straight through the earth?
| ajross wrote:
| FWIW, the object in the linked article is visible, so while
| that's an interesting theory it's actually ruled out if this
| thing turns out to be a planet. The black hole would need to be
| Planet 10 I guess.
| lazide wrote:
| At the distances described, available passive light flux is so
| low, it could be 100% painted with white titanium dioxide paint
| and we'd be lucky to ever see it. It doesn't need to be a black
| hole to be effectively invisible.
| perihelions wrote:
| Indeed, it's a doubly inverse-squared law: one 1/d^2 factor
| for how far it is from the sun, by how much the solar flux is
| reduced; and one 1/d^2 factor again for how it is from Earth-
| based observers. 1/d^4, a quartic law.
|
| That's the idea behind this paper (and similar ones like it):
| since they're looking for the planet's intrinsic emissions,
| from its internal heat, it's only a _single_ inverse-square
| law.
|
| With _d_ being ~20 times Neptune 's distance and ~140 times
| Jupiter's, these really are large factors!
| Projectiboga wrote:
| If it were earth mass it would be ~grapefruit size. This
| estimate puts object nine at 9 earth mass so maybe vollyball
| size or melon size? https://www.astronomy.com/science/is-
| planet-nine-a-black-hol...
| tlogan wrote:
| If I'm remembering right, compressing all of Earth's mass
| would give a Schwarzschild radius of roughly 9 mm. I think
| Uranus (15x heavier than earth) would be like basketball.
|
| Is my calculation correct?
| Qem wrote:
| If it were a blackhole it wouldn't show up in IRAS and AKARI
| infrared maps.
| tremon wrote:
| Wait, are you saying we have infrared maps showing planet
| 9?
| IAmGraydon wrote:
| For god's sake man read the article before you comment.
| bobmcnamara wrote:
| Would probably be a screamer on x-ray though.
| XorNot wrote:
| Not without an accretion disk, and why would it have one?
| It would've cleared it's orbit.
| AIPedant wrote:
| I think "15 times further from the Sun than Pluto" is more
| meaningful for most readers than "700 times further from the Sun
| than Earth." If it exists, it's way way way out there.
| ck2 wrote:
| There's an episode on "Space & Beyond" where they show all the
| planets in scale to the realworld on an actual football field.
|
| Then to show Planet 9 distance they have to get in a car and
| drive a few miles.
|
| That worked for me.
| 7373737373 wrote:
| My favorite: Cody'sLab's "How far away are the nearest
| stars": https://youtube.com/watch?v=dCSIXLIzhzk Also gives an
| intuition for how incredibly bright stars shine
| oxidant wrote:
| I think Bill Nye has something similar, too.
| WillAdams wrote:
| Yeah, when the solar system was introduced to my class in
| grade school, we had an outdoor excursion where the teacher
| brought out a golfball and place it at one end, then brought
| out various tiny things (noting scale was very approximate)
| and paced off each to show the relative distances.
| Nevermark wrote:
| I have a set of twelve books by an artist, titled
| "Astronomical" (one book for each letter). The first page
| shows the sun, then the rest of the books are almost all
| simply black pages, but with the planets and asteroid belt
| entities shown with accurate distance and size scale.
|
| It communicates the scales really well, while only taking up
| a little over a foot of bookshelf space when not being
| "navigated". I have two heavy metallic retro looking rocket
| bookends for it.
| 1970-01-01 wrote:
| Yes, also being 10x the mass of Earth that far out hints that
| it may be an interstellar object captured by the Sun.
| nonethewiser wrote:
| Forgive my ignorance but how is that different than the rest
| of the planets?
| tliltocatl wrote:
| The rest of the planets are theorized to have condensed
| from the protoplanetary disk that formed the same molecular
| cloud the Sun did. I. e. they have formed at approximately
| same time as the sun and from same material, sans
| gravitational separation.
| swayvil wrote:
| Ah, so a captured body would be quite different and
| alien. Really old too. Like, first generation of stars.
| s1artibartfast wrote:
| Not at all implied. It could be boring and younger too.
|
| 10x earth masses usually implies a gas giant.
| geuis wrote:
| Would likely be older than the solar system itself.
| Probably not first gen star old, but likely would have
| formed before the sun did. Don't know how different it
| would be though. Would have formed out of maybe different
| ratios of elements than what was in the molecular cloud
| we formed from, but otherwise a large body like this
| would have undergone similar geological processes as our
| own planets.
| libraryofbabel wrote:
| The other planets formed from material in the same nebula
| (cloud of gas and dust) that collapsed to form the sun. The
| idea here is this planet would have been moving through the
| interstellar medium and just happened to pass close enough
| to the sun's gravity well to get captured in a (very
| distant) orbit.
| 01HNNWZ0MV43FF wrote:
| Capture would be like a reverse gravitational slingshot?
| This planet happened to meet the sun at an angle where it
| lost enough energy to fall into orbit instead of slinging
| back out like those comets that come around on long
| cycles?
| tough wrote:
| gravitational capture
| marcosdumay wrote:
| AFAIK, it could be in a 2 bodies slingshot, multi-body
| interaction with some other stuff on the Oort cloud, or
| tidal interaction (what could happen way more easily with
| a nebula).
| noah_buddy wrote:
| A comet coming back on a long cycle is an orbit
| s1artibartfast wrote:
| You don't need to lose energy to enter orbit any more
| than you need to lose energy too roll a ball down a hill.
| tliltocatl wrote:
| Not true. An obit is not an infinite "plain" with a
| finite "hill" on but rather a finite "valley". The ball
| will exit the valley on the other side unless it loses
| excess kinetic energy somewhere in the valley.
| s1artibartfast wrote:
| Correct, but my point is you don't need to lose energy to
| enter orbit.
|
| You don't need complex reverse slingshot interactions.
| You just need a low enough relative velocity to not shoot
| off the other side.
|
| I would expect this to be the norm for capture, not some
| exotic phenomenon.
|
| A ball doesn't need to lose energy to be captured in a
| valley either.
|
| You just apply a radial force to turn a line into a
| circle.
|
| Anything that approaches the sun slower than escape
| velocity will be captured.
| dotancohen wrote:
| To all other readers: this is wrong.
| ars wrote:
| That is not true. If it approaches with less than escape
| velocity it will gain all the velocity necessary to
| escape in the process of approaching the Sun.
|
| You could think of it as speeding up as it falls toward
| the sun, it then slows down by the exact same amount as
| it leaves the Sun.
|
| In order to stay near the sun it needs to lose some of
| that speed, and given that momentum is conserved, the
| only possible way is to either hit the Sun or send that
| momentum to a third object.
| tliltocatl wrote:
| Anything that approaches the sun will do so with faster
| than escape velocity because the gravitational potential
| energy gets converted into kinetic during the approach.
| Newtonian mechanics is time-reversible - just like it's
| impossible for an object in orbit to spontaneously escape
| without gaining energy from somewhere first, it's
| impossible to enter orbit without losing energy to
| another body.
| btilly wrote:
| It would be like a reverse gravitational slingshot, in a
| different way.
|
| There is no way to capture with just 2 bodies - it would
| have to leave on gthe same hyperbolic orbit that it
| arrived on. However if it drove by and had a close enough
| interaction with a third body, like Jupiter, it could
| lose angular momentum to the planet, resulting in
| entering an orbit around the Sun. Further gravitational
| interactions with planets could then smooth that orbit
| out over time.
|
| Alternately this could be the more straightforward
| scenario of interstellar object hits planetoid, they
| merge, and the new combined object is now in orbit.
| water-data-dude wrote:
| I wanted to get a sense of what that MEANS relative to the
| rest of the gas giants. Apparently it'd be roughly the size
| of Uranus or Neptune.
|
| I guess I'd always put all the gas giants in the same "very,
| unimaginably big" bucket. I knew Jupiter was the biggest,
| then Saturn, but I didn't realize just HOW big they were
| compared to the rest. At the risk of stating the very, very
| obvious, Jupiter is huge!!!
|
| Masses of gas giants are: Jupiter, 317.8 earth mass; Saturn,
| 95.2 earth mass; Neptune, 17.1 earth mass; Uranus, 14.5 earth
| mass
|
| [0] https://en.m.wikipedia.org/wiki/Earth_mass#Unit_of_mass_i
| n_a...
| mncharity wrote:
| So Earth-mass orders-of-magnitude go something like: [big]
| 3 Juno, [balls] Ceres, Io, Moon, Mars, Earth, [gas] Uranus-
| Neptune, Saturn, Jupiter and super-Jupiters, [fusion] brown
| dwarfs, stars... .
| NikkiA wrote:
| I dunno, '700 AU' gelled for me instantly, '15 times the
| distance to pluto' doesn't even make sense given pluto's orbit
| isn't anywhere near circular.
| doubletwoyou wrote:
| I don't think the vast majority of people will have a good
| sense of how far away the standard gas giants and pluto are
| from the sun in terms of AU.
| AIPedant wrote:
| It makes even less sense for Earth because Earth's orbit _is_
| near-circular, whereas Planet 9 's hypothesized orbit is
| highly eccentric, more so than Pluto.
|
| Most people don't know off-hand that Pluto is ~40-50AU from
| the sun, so 700AU is hard to conceptualize.
| LeifCarrotson wrote:
| And Neptune orbits at 30 AU with very low eccentricity, "of
| course."
|
| https://xkcd.com/2501/
| dragonwriter wrote:
| > Most people don't know off-hand that Pluto is ~40-50AU
|
| ~30-50AU if you are referring to the range of orbital
| distance.
| rainsford wrote:
| It's sort of amazing to me that the Sun can capture objects
| that far away. Like obviously even at that distance the Sun
| would be by far the closest massive thing, but it's hard to
| comprehend the effects of gravity being strong enough at that
| distance. From "Planet 9" the Sun probably wouldn't
| significantly stand out from all the other stars in the sky,
| yet you'd be orbiting it.
| 8bitsrule wrote:
| That IS better, but I like ~0.011Ly too ... the nearest star is
| about 4Ly away.
|
| Another perspective on the size of the solar system, like the
| Pale Blue Dot.
| bsdetector wrote:
| Would this be far enough out to use the sun's gravitational
| lensing to image distant planets?
|
| It seems like the idea was to send a bunch of instruments way
| out and then take pictures in the brief time they were at a
| useful distance, but if there's a planet out there we can orbit
| and so stop the instruments at that distance it seems like we
| could make a permanent super telescope.
| fallingknife wrote:
| Probably easier to just put it in solar orbit at that
| distance. Orbital velocity is only about 1km/s at 700 AU.
| codesnik wrote:
| orbiting a planet in that case is no different than orbiting
| a sun on the same orbit as planet. Probably even more
| cumbersome, all that jiggling around. Or are you talking
| about making a gravity assist to turn the orbit of the probe
| into less eccentric?
| perihelions wrote:
| This _cannot_ be evidence of Planet 9 (the Batygin and Brown
| hypothesis)--it 's outright incompatible with it.
|
| https://bsky.app/profile/plutokiller.com/post/3lnqm2ymbd22r
|
| If those two spots are the same object, that object is on a high-
| inclination orbit; but the pattern the Planet 9 hypothesis
| explains is only compatible with a low-inclination object.
| sph wrote:
| The guy killed Pluto and still he isn't done :(
|
| Seriously though, is he one of the people responsible for
| Pluto's demotion to dwarf planet?
| ufo wrote:
| His team discovered Eris and many other trans-neptunian
| objects, which did fuel the discussion behind pluto's
| demotion: greatly increase the number of planets, or demote
| pluto? They're also behind the Planet 9 theory that's
| discussed in the article.
| db48x wrote:
| Nobody killed Pluto.
|
| Back in the early 1800s children used to memorize the names
| of the 12 planets: Mercury, Venus, Earth, Ceres, Pallas,
| Juno, Vesta, Mars, Jupiter, Saturn, Uranus, and Neptune. But
| then in 1845 astronomers discovered Astraea, and now there
| were 13. In 1847 three more were discovered: Hebe, Iris, and
| Flora. Then Metis, Hygiea, Parthenope, and Victoria by 1850.
| The 100th asteroid was discovered in 1868, and the pace only
| got quicker from there. Somewhere along that line people
| started using the words "asteroid" and "asteroid belt" and
| schoolchildren were mercifully spared the pointless task of
| memorizing hundreds, and later many thousands, of names of
| asteroids.
|
| The same thing happened to Pluto. Just as Ceres was the first
| discovered asteroid, Pluto was the first discovered TNO.
| There are now hundreds of named TNO and thousands more that
| are just numbered. Nobody should force schoolchildren to
| memorize them all. Just tell them that there are an unknown
| number of objects in the Kuiper belt and the Oort cloud and
| they'll know as much as they need to know. Give them bonus
| points if they know the names Ceres and Pluto, and more if
| they know why these two were discovered first of all the
| objects in their class: they're the biggest. Otherwise
| there's nothing special about them.
| raverbashing wrote:
| Nah, if it is big, and at that distance, and follows an
| elliptical orbit then yes it will be "Planet 9^W 8"
| rozab wrote:
| Isn't this exactly how Pluto was discovered? Due to an
| innacurate estimate of the mass of Neptune (not corrected until
| Voyager I think), people were hunting for a large planet to
| explain the discrepancy. After a bunch of searching they
| happened to find Pluto, but it was not the Planet X they were
| looking for. The mass estimates for Pluto were gradually
| downgraded from many Earth masses to 1/500, which is the true
| reason it was initially classified as a planet.
| Qem wrote:
| For a time pluto had good estimates for his small size, but
| poor constraints on his mass beyond this Neptune mass
| estimate. So I remember reading a short story were they
| interpreted the possible high density as signs of a stargate.
| philistine wrote:
| Yeah. If Pluto had been slightly heavier, we'd probably have
| ended up with a definition of a planet that included its mass
| instead of clearing its orbit to keep Pluto a planet. But
| Pluto was cooked when we figured out it's not really heavier
| than Ceres.
| Qem wrote:
| Perhaps searching for Planet 9 we went straight to Planet 10.
| There was another one and we happened to find it first. Or also
| it could be a nomadic planet undergoing a close encounter with
| the solar system.
| K0balt wrote:
| I hope this turns out to be wrong. I'm still holding out for a
| primordial back hole Planet X. That would be soooo cool and
| unbelievably useful.
| jsbisviewtiful wrote:
| Why useful? Considering how hard of a time astronomers are
| having to simply find it it's hard to imagine it being easy to
| study.
| mrshadowgoose wrote:
| A black hole in our solar system is basically "in our
| backyard" in relation to typical interstellar distances.
|
| Sure, we wouldn't be able to get there for many decades, but
| "within a century" would be feasible.
|
| There are so many unknowns surrounding the nature of black
| holes. Having one in our backyard would give us a chance to
| test our guesses.
| jiggawatts wrote:
| A black hole reachable in a human lifetime with ordinary
| chemical rockets would be an amazing laboratory for extreme
| physics.
| andrewflnr wrote:
| Yeah, finding it is hard, but once you've found it, sending a
| probe would be totally doable. I think it would be worth it.
| anthk wrote:
| Well, 9front guys now have a fancy release name.
| doublerabbit wrote:
| Can I move to Planet9? Anywhere is better than this planet.
| Qem wrote:
| With current spaceships you would die of old age long before
| arrival.
| tiahura wrote:
| How can we spot planets in other galaxies when we can't even be
| certain how many planets are in our solar system?
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