Caltech Astronomers Say a Ninth Planet Lurks Beyond Pluto (sciencemag.org) 258
sciencehabit writes: The solar system may have a new ninth planet. Today, two scientists announced evidence that a body nearly the size of Neptune — but as yet unseen — orbits the sun every 15,000 years. During the solar system's infancy 4.5 billion years ago, they say, the giant planet was knocked out of the planet-forming region near the sun. Slowed down by gas, the planet settled into a distant elliptical orbit, where it still lurks today.
Here's a link to the full academic paper published in The Astronomical Journal.
Well, I guess we'll know in a few thousand years (Score:2)
With a 15,000 earth-year long orbit of the sun, it could be a while before this is anything more than an inference.
Re:Well, I guess we'll know in a few thousand year (Score:5, Interesting)
Again, from TFA, we could perform a narrow infrared scan of the possible path until we find it. (We just did one ruling out "Saturn-sized" objects nearby, but this planet is smaller.) The authors expect discovery and confirmation within about 5 years.
scheduled for demolition (Score:3)
Let's hope we get to observe it before the Vogon constructor fleet arrives.
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Re:Well, I guess we'll know in a few thousand year (Score:5, Informative)
Not really. There's going to be some very powerful telescopes involved in survey work coming online over the course of the next decade that should dramatically increase our detection capability. My favorite is the LSST [wikipedia.org] which should, for example, move from our current knowledge of about 1% of 100km+ KBOs to nearly 100%. And one can expect even more powerful telescopes in the decades after that.
Next decade, whenever anything is detected, we'll also have James Webb to get a better look at it.
Re:Well, I guess we'll know in a few thousand year (Score:5, Funny)
Next decade, whenever anything is detected, we'll also have James Webb to get a better look at it.
If we're lucky, James will bring his telescope. :-)
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Waiting for Nibiru / Planet X morons.... (Score:5, Funny)
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To tell us how this planet oscillates the chemtrails so the 911 nuclear aliens can open up communications with the illuminati and space lizards to bring on the new world order and force us into fema camps.
^^^ Pure win.
Well... (Score:5, Funny)
It IS Planet Nine from outer space.
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Come to think of it, maybe I'd join them.
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To tell us how this planet oscillates the chemtrails so the 911 nuclear aliens can open up communications with the illuminati and space lizards to bring on the new world order and force us into fema camps.
No problem. We'll just flee and hide in the center of earth, since it's hollow...
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Perhaps Sitchin was right... (Score:2, Funny)
...and here comes Nibiru [wikipedia.org]?
Hint: +1 Funny
Lets call it ... (Score:2)
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There is already a planet with that name.... so, in true gamer fashion, we will not let that deter us.
We shall call it: xXPlutoXx
Pluto can be a planet again (Score:5, Funny)
Step 2: Name the new planet Pluto
Step 3: Profit!
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Cupid?
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https://en.wikipedia.org/wiki/... [wikipedia.org]
Pluto is Mickey's dog, not Goofy's.
Don't believe it (Score:2)
Dear Ethan (Score:5, Insightful)
Please read TFA and consider it a good example of how to write something informative, accessible and entertaining, but most importantly not hosted on forbes.
I KNEW IT! (Score:5, Funny)
This finally explains all the times my horoscope wasn't entirely accurate. With this new input, I'm sure that I will be able to use my horoscope to see what the stars have for me and I will be able to intelligently make life-decisions knowing how they are arranged.
N.B. - I started the above in jest, but let's observe a moment of silence for the poor folks who actually feel that way.
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Careful. You're going to end up having to explain accuracy and precision and their differences if you keep making sense like that.
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Horoscopes are almost always "accurate."
A typical horoscope in the paper:
"Virgo - look both ways before crossing the street."
See? Accurate!
The advice is good, but incomplete.
His pattern indicates two-dimensional thinking.
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I like Dara o'Brian's notion that racism is way better than astrology. You know, there's only 12 zodiac signs that people can have, but racists can easily break the world up into far more groups than that. Just bring in a racist daily to write the forecast for you. "It's going to be a good day for the Jews...."
Does it count as "evidence" (Score:4, Funny)
This is a prediction by a hypothesis - nothing more. I could create a model that predicts the existence of dragons that fart nerve gas - that does not count as "evidence of an impending apocalypse," although that would surely generate many clicks.
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Re:Does it count as "evidence" (Score:4, Informative)
It is a hypothesis which is supported by evidence. The existence of Jupiter is also a hypothesis which is supported by evidence, although much stronger evidence than the evidence for this planet. Epistemology is frequently at odds with our every day feelings about knowledge.
Re:Does it count as "evidence" (Score:5, Informative)
You really need to read the articles. To quote from one of them:
But the real kicker for the researchers was the fact that their simulations also predicted that there would be objects in the Kuiper Belt on orbits inclined perpendicularly to the plane of the planets. Batygin kept finding evidence for these in his simulations and took them to Brown. "Suddenly I realized there are objects like that," recalls Brown. In the last three years, observers have identified four objects tracing orbits roughly along one perpendicular line from Neptune and one object along another. "We plotted up the positions of those objects and their orbits, and they matched the simulations exactly," says Brown. "When we found that, my jaw sort of hit the floor."
"When the simulation aligned the distant Kuiper Belt objects and created objects like Sedna, we thought this is kind of awesome—you kill two birds with one stone," says Batygin. "But with the existence of the planet also explaining these perpendicular orbits, not only do you kill two birds, you also take down a bird that you didn't realize was sitting in a nearby tree."
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Matched exactly? Oh really?
Re: Does it count as "evidence" (Score:2, Interesting)
Perturbations of other (dwarf) planets and KBOs is exactly what they are basing this claim off of.
That data strongly supports a massive body well outside Neptune's orbit, but until now no one could say if it was a large planet farther out, or an Earth-sized planet closer in (relatively). Some people even suggested it could be a brown dwarf binary very far out.
These guys have now used the preexisting data to predict that it's a smaller planet "close" in based on computer modeling.
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Re:Does it count as "evidence" (Score:5, Informative)
If you read the article (I know, I know), you'll learn that there are, in fact, observables involved. There are a handful of Kuiper Belt objects that have an odd level of similarity among them, so odd that the only ready explanation is that there is an as-yet unseen object shepherding them. The Caltech group created a simulation of the kind of object that might produce such a result and found that it ALSO would be expected to shepherd a second set of smaller objects into orbits orthogonal to the ecliptic. Very, very strange. So they made that prediction, and LO! found objects that fit the bill.
They created a theory based on observational evidence. The theory made a prediction that was tested, and found correct. The body itself has not been observed, yet, but I'd expect that the Japanese will find it (given that, according to other news articles), they have just the right sort of telescope to perform the search.
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The evidence is the observed orbital properties of distant Kuiper belt objects. The computer model is just used to validate possible explanations. This is almost exactly how Neptune and Uranus were discovered: by observing their effects on the orbits of the then-known planets.
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They already had the evidence (Score:2)
The evidence consists of the observations which inspired them to make the computer model.
They already had the evidence; they just didn't know what it was evidence of. And then once the model predicted stuff like Sedna's orbit, they then had even more evidence: Sedna-and-friends. So that was an additional complex of evidence, for which they previously didn't know what it was evidence of.
Let's say you drop an apple out of a tree. It falls. You don't know why. Then someone notices that most of the apples eve
In a dark office somewhere... (Score:2)
Star Blazers gets it right again. (Score:3)
Space Cruiser Yamato (AKA Star Blazers in the USA), not only predicted Pluto's moon, but also a 10th planet -- I think it was called Brumus in 2nd Season (Comet Empire).
Can't remember too much because it was more than 20 years since I saw the show, but so far, their space science is more true than any other TV show I can think of.
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Some thoughts (Score:5, Interesting)
An interesting thought. Even at its perihelion (1100 AU), helium won't be getting cold enough to condense out. But hydrogen probably will, condensing to planetwide hydrogen seas. Meaning that - combined with its lower mass - its atmospheric density at perihelion on top of that is probably surprisingly low. However, at aphelion its only about 400AU. That's probably not cold enough to condense hydrogen. So every 15000 years it would go from having hydrogen oceans and low atmospheric pressure to an ice surface under crazy pressures.
What the heck do you call a planet like that?
Such a large planet would certainly have the internal heat for tectonics and volcanism. But I'm still so baffled from trying to picture what such a planet would be like just from that first aspect that I can't even begin to imagine what effect the latter would have on it.
Certainly a lot of energy in play here.
Re:Some thoughts (Score:5, Interesting)
More thoughts.
1) The atmosphere would be pure - 100% pure helium. The only thing that could contaminate it would be hydrogen, so if it's cold enough for it to be fully condensed out (no hydrogen clouds/rain), then it'll be a monoatomic gas. No clouds.
2) The hydrogen seas would also be pure. There's almost nothing that can float in hydrogen - pretty much just foams gassed with helium, and that doesn't sound likely.
3) Weird nuclear properties: helium is a perfect neutron moderator - it never undergoes neutron capture. It can undergo high energy reactions, but at lower energies, any neutron in helium will become fully thermalized, which - at those temperatures - would make everything interact with it at a very high cross section. Since only helium would be in the atmosphere, that would most likely be 3He. So I would expect 3He depletion.
4) The day length would change when the hydrogen condensed out (like a ballerina pulling her arms in). I'm not sure off the top of my head of the effects of this mass redistribution on any orbital bodies, although I could picture, say, enhanced tidal heating due to the mass redistribution.
5) There's an awful lot of potential non-hydrogen liquids which could exist under the liquid hydrogen (or under the H2/He atmosphere near aphelion) - nitrogen, carbon monoxide, methane and other hydrocarbons, neon, even water. It all depends on the pressure and temperature curves, which one couldn't even begin to speculate on at this point. Most of the latter could potentially form eutectics, but hydrogen is not prone to forming eutectics, so would make its own distinct surface layer.
6) Lava flows of any type (silicate, cryolavas, whatever) would happen underneath the hydrogen ocean. Meaning pillowing. The boiloff of hydrogen could then expose these structures. What do pillow cryolavas formed under hydrogen look like? I haven't the foggiest.
7) Any hot lavas (such as silicates) erupting into liquid hydrogen might have unusual chemistry (metal hydrides and the like? extensive hydrocarbon formation? silanes, stabilized by the low temperatures?). This would then be left exposed on the surface when the hydrogen boils off. That surface could be a really bizarre place.
Any other thoughts?
Re:Some thoughts (Score:4, Funny)
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Ugh.... can't believe I mixed those up... :P
counting is fun (Score:3)
Re:counting is fun (Score:4, Informative)
The concept that dark matter wasn't normal matter wasn't arrived upon easily, it took until the 80s to really accept it. The thing is, even small objects still interact with EM radiation and such, and this has effects if you want to have enough of them to account for the missing mass. And these interactions just aren't observed, no matter what size bodies you assume. The closest you can get out of conventional matter is a hypothesis is for hypothetical objects called "macros", which is basically like tiny neutron stars.
Honestly, dark matter doesn't bother me at all. What's so weird about the concept of particles having little to no interaction with certain fields? Now dark energy, that's some evil sorcery there....
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Planets are a fraction of a percent of the mass of the solar system. When studying the structure of the galaxy astronomers could just use the sun and ignore the mass of all the planets and it wouldn't make much of a difference.
When found the name needs to start with P (Score:2)
When it is actually found and they decide to name it, the new name needs to start with P so all the mnemonics that used to work with Pluto as #9 will work with this new planet.
From Wikipedia:
"My Very Educated Mother Just Served Us Nine Pizzas"
"My Very Easy Method Just Shows Us Nine Planets"
"My Very Efficient Memory Just Stores Up Nine Planets"
"Mary's violet eyes make Johnny stay up nights, pondering"
Persephone might work.
Cleared it's neighbourhood (Score:2)
What does the solar system look like out at the distance of this suspected planet? One of the reasons for demoting Pluto to dwarf planet status was that it hadn't cleared it's neighbourhood so if this new object is orbiting in an area where there is lots of other materials then it shouldn't be called a planet either.
5 Planets visible together (Score:3)
Since we're on the subject of the Solar System a relatively rare phenomenon is occurring Jan. 20 to Feb. 20. [earthsky.org] All five of the easily visible planets (Mercury, Venus, Mars, Jupiter, Saturn) are visible together in the early morning sky. The last time that occurred was Dec./Jan. 2004/2005. They will be visible together again Aug. 13 to 19 but will be more easily seen in the Southern Hemisphere because Mercury and Venus will be difficult to see in the dusk sky.
Ninth, mofo. (Score:3)
Ninth. If you RTFA you'll see that the paths of many of the other semi-small dwarf planets were used to intuit the existence of a real ninth planet.
Re:Ninth, mofo. (Score:5, Funny)
Re:Ninth, mofo. (Score:5, Funny)
>> Dwarf planets are not planets any more than dwarf people are people.
Dwarf planets are not planets any more than daddy long-legs spiders are not spiders.
Dwarf planets are not planets any more than Komodo dragons are not dragons.
Dwarf planets are not planets any more than Fool's Gold is not gold.
I think we can agree that English isn't the best language for science. Where are we going with this?
Re:Ninth, mofo. (Score:5, Insightful)
I'm not sure why you inserted "not" before the predicates of the subordinate clauses in your sentences. You changed the structure of the analogy.
Re:Ninth, mofo. (Score:5, Funny)
I think we can agree that English isn't the best language for analogies. Where are we going with this?
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Dwarf planets are not planets any more than daddy long-legs spiders are not spiders.
er, Pholcidae are most definitely spiders.
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Dwarf planets are not planets any more than daddy long-legs spiders are not spiders.
er, Pholcidae are most definitely spiders.
OK but they're not daddies.
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Wikipedia makes reference to all three species as "daddy longlegs". If you're going to quibble about "daddy longlegs" vs "daddy longlegs spider", here's an article referencing Pholcidae as "daddy longlegs spider": http:/ [ucr.edu]
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Is Dwarf Star a classification of stars or an entirely different thing?
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>> Dwarf planets are not planets any more than dwarf people are people.
Dwarf planets are not planets any more than daddy long-legs spiders are not spiders.
Dwarf planets are not planets any more than Komodo dragons are not dragons.
Dwarf planets are not planets any more than Fool's Gold is not gold.
I think we can agree that English isn't the best language for science. Where are we going with this?
Two and three are correct, but there definitely is a real daddy long-legs spider. It's just that most people misidentify an creature known as a harvestmen as a daddy long-legs spider, which obviously, it is not.
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>> Do you mean harvestmen (opiliones) or cellar spiders (pholcidae)?
Opiliones, for sure. Even my three-year-old daughter knew it was OK to pick up the former and squish the latter.
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Re:Ninth, mofo. (Score:4, Insightful)
We prefer the term 'compact planet'.
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Fun size.
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If Dwarf People aren't really people then is Dwarf-Sex really Sex ?
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you racist
Actually, little people aren't a separate ethnicity. So racist is the wrong term to use. Bigot would work, however.
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Sorry, but many of us feel that the IAU's redefinition was a huge mistake. Including for example most of the New Horizons team. Heck, even when you press supporters of the concept of defining planets based on orbital characteristics rather than hydrostatic equilibrium you find that even most of them will admit that the definition as it stands is a mess and should be revisited. It's self-contradictory, vague, full of holes and creates more linguistic confusion than it solves.
It's worth adding that if we g
Re:Ninth, mofo. (Score:5, Funny)
It's kind of like the term "marriage". Its meaning is different depending on who you ask. Some believe it is a religious concept, some believe it is a legal concept, and some feel it is both.
I think we can all agree that the proper term for Pluto is "gay planet".
Re:Ninth, mofo. (Score:5, Funny)
It's actually a trans planet. Trans-neptunian that is.
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I would call it closer to Goofy
Re:Ninth, mofo. (Score:4, Interesting)
Yeah that was the first thing that went through my mind - Under current planetary evolution theories, despite it's size it has almost certainly not cleared it's neighborhood.
Which is of course the *exact* problem many people had with the definition, and I really hope this turns out to be real and they have to deal with a 'Dwarf Planet' ten times Earth Mass.
Re:Ninth, mofo. (Score:4, Interesting)
It has as mentioned a semi-major axis of around 700AU. That's 23 times more than Neptune. It has a mass of about 10Me, or 58% of Neptune. Its Margot discriminant would be less than a tenth of Mars' (lowest in the solar system). Plus, it's highly elliptical (e=0.6), meaning it has a far broader neighborhood to clear (something not taken into account in the discriminant).
Planetary scientists wanted a definition based solely around hydrostatic equilibrium; the main group pushing for an orbital dynamics definition was astrophysicists. The original draft was based around hydrostatic equilibrium, so many of them left, content that they'd either get a hydrostatic equilibrium definition or no definition at all.
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Heck, Jupiter hasn't cleared its neighborhood. The Trojan and Greek asteroids are in the same orbit as it, I guess we have to demote Jupiter next.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:Ninth, mofo. (Score:5, Interesting)
The whole "cleared the neighborhood" thing is based on a lie anyway. The vast majority of planets didn't clear their neighborhods. Jupiter**, and to a lesser extent Saturn, did. Mars' lack of influence on its neighborhood can be seen by how low of a percentage of asteroids are in a resonance with it.
Can we stop with the pretending that planets like Mars are responsible for sweeping their orbits clean? No models support this.
It's funny, but you see almost the exact same reason given by everyone interviewed who voted for the IAU definition - always a variant of "I don't want my daughter to have to memorize the names of 50 planets". As if that's even remotely any sort of scientific argument, as if we should say there's only 8 rivers in the world or 8 bones in the human body and all others are "dwarf rivers" and "dwarf bones" that aren't really rivers and bones, in order to make it easier for schoolkids.
They had their preconceived concept - they wanted a low, memorizeable number of planets - and tried to create a definition to fit it. And failed miserably at it. Now we've got a definition where a "Dwarf X" is not an X, despite the fact that in astronomy (and almost everywhere else) "Dwarf X" always denotes a type of X - dwarf stars, dwarf galaxies, etc. We've got a definition based on poorly defined concepts like "neighborhood". We've got a definition that arbitrarily excludes exoplanets from being planets, which is a terminology disaster. We have a definition that runs contrary to what people associate with the word "planet" - they expect "big round object floating through space around a star" - if it's pulled itself into a sphere, they think "planet", if it's lumpy then they think "not a planet".
We had a perfectly good dividing line: hydrostatic equilibrium. It's not just what the public expects the word to mean. Collapse into hydrostatic equilibrium produces altered minerals, releases of energy, fluids, and all sorts of things - they're the place you'd go to study planetary evolution, search for life, etc. Bodies that have not collapsed into hydrostatic equilibrium are where you'd go to study primordial materials, the origins of the solar system, etc. They're fundamentally different bodies.
And for that matter, what sort of nonsensical grouping is it that says that Mercury is more like Jupiter than it is Ceres? Want to pinch off some bodies from the list of planets? Go all the way. We have the inner planets, we have the gas giants, we have the ice giants.... IMHO I really like Stern's multi-classification approach. You have an adjective which describes the size and whether it's in hydrostatic equlibrium - say, superdwarf, dwarf, giant, supergiant, etc; you have a compositional term, such as terrestrial, gas/hydrogen, ice, etc - and you have an orbital term, such as "planet" (body that orbits around a star), "moon" (body that orbits around a planet"), and so forth. When describing a body, you can use as many or as few of the components as you need to.
(** Hell, if I really wanted to nitpick, I could point out that the definition requires planets orbit the sun. Jupiter orbits the Sun-Jupiter barycentre, which is not inside the sun. You can say "close enough", but where do you draw the cutoff line?)
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(** Hell, if I really wanted to nitpick, I could point out that the definition requires planets orbit the sun. Jupiter orbits the Sun-Jupiter barycentre, which is not inside the sun. You can say "close enough", but where do you draw the cutoff line?)
Wait...what? I had no idea. My intuition has always been that the Sun is so massive compared to the planets that of course the barycenter was inside the sun. But, the sun being "only" 1000 times as massive as Jupiter means that the barycenter is about 1/1000 of the way between their center of masses, which puts it just outside the sun.
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These IAU peeps can suck eggs.
I will continue to call Pluto a planet despite what some overgrown astronomy club thinks it should be called.
There's too many diverse celestial objects to try and identify with legalese. The U.S. Government can't even describe a home loan in less than 10k pages, the trend these boffins suggest would deforest this planet and any others found to posses fibrous growths that could be used for paper.
Occam's Razor: Planets are spherical and orbit a sun, moons can be any shape and orb
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Occam's Razor: Planets are spherical and orbit a sun, moons can be any shape and orbit planets.
Done.
I prefer a definition where planet and moon are not mutually exclusive. The object most like Pluto by mass and composition in the solar system is Triton, and vice versa. They probably both started out with similar orbits in the same region. Then one was captured into Neptune's orbit, and the other only captured into Neptune's orbital resonance. One therefore is a moon, but I would argue that both should be considered planets as they are equal in every way except by accident of location. So I propose that a
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IAU Definition (Score:2)
Pluto and various other plutinos [wikipedia.org] are in orbital resonance with Neptune, which is the dominant gravitational body in Pluto's orbital band. Yes, there are fewer objects in the Solar System which are gravitationally dominant in their orbits, but it's not an arbitrary criterion, even if it has the effect of excluding many small solar objects. "Dwarf planet" does in fact refer to, well, dwarf planets: objects of the appropriate size, orbiting the sun, which have not cleared their orbit. Objects smaller than that
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'Clearing the neighborhood' means that it is the gravitationally dominant object in that orbit.
Since when is that an accurate parsing of the phrase?
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Agreed, as hardly is the orbit cleared if there is all kinds of crap in the lagrange points.
Orbital Cleaning Services - 1 gigadollar/teraliter (Score:2)
Well then get a broom and get out there. You have the whole solar system to do! Quick, or we won't have any planets at all!
Or you could, you know, accept that there's always going to be some degree of crap in Lagrange points. They're still under the gravitational control of the larger orbiting body, which was kinda the point: we're only counting the big things that go around the sun, not the big things that go around the sun but have weird gravitational relationships with other bodies.
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I wasn't commenting on the Lagrange Point objects. My point was simply that "clearing the neighborhood" does not mean being the "dominant object in that orbit". They are two entirely separate things, even if they are intrinsically tied together in a solar system. But one does not mean the other, one is not the defining characteristic of the other.
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Don't get Kepler to do it. He'll just sweep out the same area every night.
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or 15th if you want to count some of the other semi-small planets.
Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, Eris what's number 14? (Charon?)
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You wouldn't say that if you cared about the children!!
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Re:I hope its true (Score:4, Insightful)
Its perihelion is over 1100 AU. Sedna was discovered at 90AU. Wee bit of a difference there. Also, the degree of the solar system we've searched varies greatly in detection ability, some areas much better studied than others. It's estimated that we've only found about 1% of KBOs larger than 100km.
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And people born in the 20's (like my dad) were taught that there were 8 planets (though not for long).
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So is grammar, apparently.
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From the article:
The planet is thought to be gaseous, similar to Uranus
Hehehehe ... um, excuse me.