Except we’ll also be arriving at Pluto. I shall try to stir from my haze enough to see the pictures from that distant whatever-it-is.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
Except we’ll also be arriving at Pluto. I shall try to stir from my haze enough to see the pictures from that distant whatever-it-is.
Assuming there are any of the encounter tomorrow. With the extremely low baud rate of transmission, it may be several days before even raw images are available, and months before anything of good quality.
Although there will be a good resolution, heavily compressed image of Pluto released later today (600 pixels across!), the best temporary images for the next few months will be arriving after the flyby from the 16th to about the 20th. (Or the next day, here in the eastern hemisphere.) The final ‘fail safe’ downlink before the flyby is scheduled between 2:23 and 3:15 UT, starting in about one hour, most of that time needed for the Pluto image, and then New Horizons goes silent for 21 hours if all goes to plan. The antenna only puts out about 12 watts of power and has the bandwidth of an old-style modem; the full set of uncompressed images are probably going to occupy many months if not years of downlinking from late 2015 onward. You have to be very patient to study trans-Neptunian objects!
I’d skip it. The Mi-go don’t like having primitive lifeforms spying on their worlds.
How long does it take to learn patience?
It’s 11 light hours away. The first real data isn’t expected until sometime Wednesday.
Could be worse. At least it’s not a probe of Uranus.
“It’s 11 light hours away.”
Only in an alternate universe where the speed of light is significantly slower. The New Horizons spacecraft and Pluto are both very close to 4.5 light hours away from Earth right now (at least in this universe).
Did astronomers ever decide what it was? First it was a planet, then it was a particularly large asteroid and part of the Kuiper belt, then it was a “dwarf planet”, and the last I heard they’d settled on plutoid.
And whatever happened to Eris? There was some big exciting announcement about a tenth planet, then it was an asteroid, then they came up with plutoids and it became one of those, and I’ve not heard anything since.
I nipped on the NASA site (they now seem to be umming and aahing about whether it’s a dwarf planet or a plutoid, but the difference between the to seems to be somewhat nebulous) and they’ve got a little bit about the New Horizon. This caught my eye:
Jesus.
I mean, there’s dumming down and then there’s just taking the piss.
Yay, New Horizons! I’ve been excited about this for months, then I came down with some form of demon flu last week and lost all track of reality and learned that today is the day from my dad, yesterday. Still, hooray for close pictures of Pluto, assuming Pluto doesn’t turn out to be a satellite-eating space monster in disguise and eat it before it gets the chance to transmit them.
@Thumper, 9
We can’t allow them to claim that Pluto is a plutoid! That would be like saying Jesus was a Christian. It’s just… wrong. In the immoral sense.
Get out yer science sledge hammer and science drill; we’re going to do some science!
Would the discovery of a new class of particles at the LHC cheer you up at all?
As for Pluto, it’s a dwarf planet and a plutoid. No, that’s not a dessert topping/floor wax reference – all plutoids are dwarf planets, but some dwarf planets are asteroids instead.
@8, 9
A planet is a body (1) in an orbit about the sun, that (2) has sufficient mass to collapse down to near-spherical shape (hydrostatic equilibrium), and (3) is also gravitationally dominant (which means all other objects at that orbital distance have either been ejected, or are in a subordinate gravitationally stable configuration: satellite or Lagrangian point).
A dwarf planet is a body (1) in an orbit about the sun, that (2) has sufficient mass to collapse down to near-spherical shape (hydrostatic equilibrium), (3) is not gravitationally dominant (and can thus have any number of other objects milling about it), and (4)* is not a satellite. So, Pluto is a dwarf planet.
Everything else orbiting the sun is a small solar system body.
Note that satellites are not SSSBs nor planets nor dwarf planets regardless of their size because they orbit their ‘parent’ object instead of the sun.
Here’s where it gets annoying.
A trans-Neptunian object (TNO) is virtually anything orbiting the sun with a larger mean distance than Neptune; comets are the exception because they are special. Pluto is a non-comet that orbits further away than Neptune, so say hello again.
A plutoid was a proposed term for any TNO that is also a dwarf planet, so pluto belongs here too. However, the term was not officially accepted and as far as I’m aware, is rarely used.
A resonant trans-Neptunian object is any TNO that with orbital period that has a stable ratio with that of Neptune. Pluto: present.
A plutino is any resonant TNO that specifically has a 2:3 orbital resonance with Neptune, i.e. orbits twice for every three Neptunian years. Hello, Pluto.
Oh and the Kuiper Belt (rhymes with ‘viper belt’) is a specific cloud of objects similar to the asteroid belt between Mars and Jupiter, except that it is far larger and far more distant: it is outside Neptune’s orbit. Consequently, all Kuiper belt objects (KBOs) are also TNOs, but not all TNOs are KBOs. And yes, Pluto is in the Kuiper belt.
SO. Pluto is a dwarf planet. And also a KBO, TNO, a resonant TNO, a plutino, and would have been a plutoid if that term became official.
*Note that (4) did not need to be mentioned in the case of a planet, as being gravitationally dominant precludes being a satellite. There are several satellites – including our very own Moon – that are massive enough to qualify as a dwarf planet (if they were not a satellite, but instead occupied a Lagrangian point), or even a full planet (if the more massive object did not exist). Thus, if Earth didn’t exist, the moon would meet the criteria to be classified as a planet… but if Earth didn’t exist, who would exist to classify it??? Checkmate, scientists! etc.
Evidently I left that window open a long while without refreshing.
Oh and I forgot to address Eris, but instead of doing the long version, I’ll just say that Eris is pretty much the same size and mass of Pluto, orbits the sun, but is not gravitationally dominant (making it a dwarf planet). Its orbit is more distant than that of Pluto, making it a TNO (and hence a plutoid if that term were official), but has not been determined to have any resonance with Neptune (and hence not a plutino nor resonant TNO of any sort). It’s distance is about right to place it in the Kuiper Belt, but is not considered a KBO due to its high orbital inclination.
Incidentally, the discovery of Eris was something of a catalyst, prompting questions of what exactly distinguished a planet from all the other stuff in orbit about the place, at which point the International Astronomical Union realised that the term had never really been assigned a specific definition due to the fact that the word had simply been handed down and accepted ‘as is’ for about 2,500 years. This brought about the big reshuffling of designations in about 2005/6, which led to Pluto losing its official status as a planet, and is responsible for a whole shitload of terminology confusion.
Thanks, Eris.
Well Eris was named after the god of chaos
Pluto is a planet…I don’t particularly care what sort of definition the IAU has come up with that removes it from the family. Eris should be considered one as well, along with Makemake and Ceres. (But not Haumea.) We wouldn’t be having this discussion if Pluto wasn’t discovered by an American.
The IAU’s definition is nonsensical in that if the “clearing the neighborhood” requirement is taken seriously Jupitar is not a planet as the ~100,000 Trojan asteroids exist.
It is such political bullshit on a stick that this “discussion” is even needed.
Google has a simplified animation of the flyby on their home page. Very apt.
Yes we would, it was only initially declared to be a ‘planet’ because Astronomers erroneously thought it was FAR more massive than it actually was. And they had no idea it was just one of a large number of similar objects in the same region.
There are funny newspaper articles at the time where Astronomers happily declare that the new planet might be larger or more massive than Jupiter.
And they were all very disappointed as estimates of Pluto’s mass kept on getting smaller.
Well that’s true enough, but then any definition is always going to be silly and meaningless. Much better idea just to class them in sets. There the terrestrial planets, meteorite belt, gas giants, ice giants and kuiper belt objects all fit neatly.
The definition given in comment 14 doesn’t seem to have that problem.
I’Ä SHUB-NIGGURATH, I hope the Mi-Go won’t seize the probe. But they seem nice enough by now, they even drew a heart on the surface.
Man, I wish Lovecraft would have lived to see this…
@ Holms #14 and 15
Good Lord, my brain hurts. Thanks though; very informative. It’s interesting that the NASA page on Pluto uses the term plutoid even though the term never became official. Perhaps the page is out of date?
I now understand the difference between the categories, but I’m afraid I’ll probably only remember the difference between planet an dwarf planet. C’est la vie; that’s the one that will come in most handy anyway :)
Have they finally reached a consensus on its EIEIO status?
Brian Pansky:
I’m happy with the classification. But if other objects at that distance are not “in a subordinate gravitationally stable configuration,” how long does it take before they’re ejected or collide with Pluto? I’m sure that’s going to be a very gradual and slow and messy process, so nobody has good predictions about that now. The point is, once that eventually happens, assuming Pluto’s not destroyed by this process (or tossed around too much), what do we call it then? Couldn’t we reassure Pluto-fanatics that some day it’ll probably grow up into being a planet?
@Brian Pansky
1) Not all Trojan asteroids are located, precisely, at L4 and L5. It is my understanding about 6,000-10,000 share that location while the other 90,000 are off those points and thus not fitting 14’s hand waving.
2) Regardless of the Trojans around Jupiter (and other planets) there are 10,000ish Near Earth Objects that will eventually collude with Earth (we have a whole program to detect them!) which means Earth is not a planet as it doesn’t clear its neighborhood.
@Tim
Pluto’s planethood was unproblematically recognized as such for over 76 years…it was only upon the discovery of planet Eris in 2005 that this whole nonsense truly begun. Not coincidentally, it was also a time in which America was at a particularly low point internationally.
There is no way to jury rig a definition that doesn’t include Pluto and the like as planet without excluding others like Jupiter. In light of this being a dispute of classification and definition it’s not really about science per se. I dont even get the pressure to try to exclude planets like Ceres and Makemake from consideration. It’s beyond odd to me that this “debate” kick started the way it did.
For the record this is definition I use for a planet…
1) The object orbits a star without orbiting another object
2)the object is large enough to be in hydrostatic equilibrium
I’m aware this results in the solar system having at least 12 planets and probably more like 100. But honestly I don’t see the problem with that as a definition is about and only about the object itself and why the hell is it a problem anyway if there are a lot of planets?
I always thought it was obvious that Pluto was a dog. Goofy is the one that I have trouble with.
Seriously, the discovery of the dwarf planet Pluto was kind of accidental, the way I recall it. The variations in Neptune’s orbit suggested a big planet on out there. Pluto didn’t fit the bill, but there it was. Fame beckoned the discoverer of a planet, so a big claim was better. Plus, Percival Lowell got a shout-out in the PL part of it, so it was getting hyped a couple different ways. I mean, the asteroids had been noticed, so a second belt would not have been unreasonable – as the Kuiper turned out to be just tbat. Patience and decision-making went out the window, though.
http://www.nasa.gov/multimedia/nasatv/
They’re doing a thing on Pluto right now.
The NASA people are consistently calling Pluto a planet. :P
You’re not thinking fourth-dimensionally. If you took all of the Trojans and did any combination of slamming them into Jupiter, moving them to Lagrangian points, or letting them escape Jupiter’s orbit, then that wouldn’t have any significant effect on Jupiter or how it moves. Because it’s a big fat planet that dominates everything else in its neighborhood. As time goes by, such things will happen because all of those trajectories you’re citing aren’t stable, where you think they “ought” to be to make things nice and clean and easy to define. So, we can very safely say Jupiter will not be very different after that. But obviously those Trojans will be, because they’ll either be destroyed or approach the (simplified and very long-term) conditions specified by the definition.
Of course, Earth might not have life on it anymore if you did the same things to it, but it would continue on its merry way as a planet which is moving in a particular orbit. Notice that there are many trillions (let’s call it zillions, because there’s no point in actually counting them accurately) of Near Earth Objects, if you’re including every last tiny thing flying around out there, so you should ask yourself why you’re only identifying the 10,000 or so which are the largest. The answer is that the rest are so small that they “don’t matter” for most purposes. So when you say “why the hell is it a problem anyway if there are a lot of planets?” the same thing goes for your NEOs. Why the hell is it a problem anyway if there are trillions and trillions and trillions of NEOs? It isn’t a “problem” — it’s that you’re trying to say something interesting about the structures and dynamics of this whole messy and complicated system that nature gave us, by coming up with somewhat-arbitrary categories for things which will make sense given the kinds of questions we’re interested in answering about them.
What does any of it have to do with America, and what makes you think that’s not coincidental?
Analogously, you can think of what we mean by “the Milky Way Galaxy” in contrast to “Andromeda” or other “dwarf galaxies” that orbit either of “them” for the time being. Or ask what is included or not included in our “Local Group”: it’s guaranteed that some things in this big muddled mess aren’t permanently “bound” to us due to the expansion of space, but for us it’s impossible to distinguish between those which are and those which aren’t. In the mean time, it’s just a fact that all of these things we’re interesting in describing and explaining aren’t yet “done” forming. So you just have to work with what you’ve got. When you’re defining things according to dynamical criteria like this (because those dynamics are what you want to study), it’s not a problem that there are fuzzy boundaries and things can/will change over time.
@consciousness razor:
But since Pluto is in a subordinate gravitationally stable configuration with Neptune, it doesn’t matter whether everything else disappears; Pluto will always be the minnow in its orbital region.
@prae:
You may be glad to know that the following are candidates for the names of features on Pluto:
Cthulhu
Yuggoth
Maybe that will placate the Mi-Go.
(But, I hope that ‘Mon Repos’, the home of Death in the Discworld books, gets used too)
I get what you mean, but how sure are you about what it will “always” be? No calculations from me, but isn’t there a chance it’ll somehow or another be dragged into a larger orbit well outside of Neptune’s? Of course there’s more Kuiper belt stuff out there, so it would still be another minnow in a big pond swarming with minnows (not a shark or a whale or whatever). Although I’m sure it would take a lot of additional luck for Pluto to have cleared everything out there somewhere, Pluto fans seem so desperate sometimes that maybe that little shred of hope would be enough to satisfy some of them.
No the planethood of Pluto was always problematical it was just ignored as much as possible for 76 years.
The discovery of Eris only brought the problem to a point where it could not be ignored any more.
Pluto is lovely, and New Horizons is a brilliant mission. I’d honestly never even heard the notion that the decision on planets/dwarf planets/Pluto had anything to do with the nationality of its discoverer, find it an odd idea, but if it’s at all calming to anyone imagining this: NASA and all US citizens who have supported its efforts can be justly proud of what they’ve achieved, today. Whatever anyone calls the target body. The vision of those in the agency who said yes, let’s go to the Kuiper Belt, let’s make that a priority, despite the time it’s going to take, that’s something to be proud of. It’s simply inspiring. I think we’re going to learn a lot from this (and who here is now trying to work out the mechanics of getting something to Sedna with its RTG still making enough power there’s actually a point)?
I don’t want to get too far into the nomenclature. Apart from to point out: as we’ve learned more about the solar system, we’ve added categories to reflect the additional knowledge, and I think that’s part of this. Terrestrials and gas giants, for some time. Then ice giants, once it became clear those were a bit different, too (thanks also to US probes, in large part). Now we classify many as dwarf planets, and yes, KBOs, TNOs, plutoids, plutinos. Now that we can survey other systems, we talk about hot Jovians, hot Neptunes, superearths. As knowledge expands, the nomenclature evolves to reflect it, and it should.
… and I also think that’s all I want to say about the nomenclature, and I guess I shouldn’t be, but I’m still a bit amazed it’s even much of an issue when there’s this richness of results coming down into the DSN. Brilliant work being done here, hard to tear your eyes away. I’ve previously pontificated on the endurance and patience it’s gonna take to study objects at greater and greater distances from us, how it may even require us to grow up a bit as a species, going from missions that require you to train grad students at launch knowing they’ll be a decade older when someone has to be ready at mission control when the probe gets there, and onto missions that may require multiple generations’ efforts to sustain… and all the same I find myself mashing refresh repeatedly on news feeds and landing pages over the past several hours, knowing damned well there won’t even be an ‘OK’ signal from the thing until 8:50 ET tonight, not likely to be much in the way of instrumental results for at least many hours after.
Anyway, again: thanks and congratulations to all involved. Good to see the frontier moving back again, by a few more AU, and to see this new class of body from so very close.
anyone bothered to define “planet.”
Well said, A.J.Milne@34
I’m finding it a little puzzling that there is hostility to the idea that astronomy came up with terminology to classify the objects orbiting the sun, purely because Pluto changed category.
Reading the thread backwards, I was intrigued at the fact that someone here of all places would be bemoaning the reclassification of Pluto from planet to dwarf planet. And then I saw who made the original statement, at 25, and couldn’t help but laugh. I was expecting a somewhat-regular, or a newbie, but not a known clown. What a surprisingly little treat.
Pictures of Pluto and Charon are up. Just a taste of Pluto….
Just for anyone interested, Clearing the neighbourhood around an orbit has well-defined measurements, with more than four orders of magnitude between some objects and others. It just so happens this gap perfectly matches up with the eight objects that are larger than any satellites, and have nearly-circular orbits. It’s actually a surprisingly non-arbitrary cut off.
The planethood debate has been done to death. I’m with Phil Plait on this–it doesn’t matter.
Much more interesting is that Pluto and Charon are geologically active worlds with a dizzying array of surface features (pointy ice mountains!) and lots, lots, more cool stuff yet to be discovered over the next 16 months.
^ Yes, it’s just a dry bit of nomenclature… which is why I find it odd that some get cranky about it.
@consciousness razor
If we add time to this and “clearing the neighborhood” means “able to have anything its orbital path smack or change without effect” that only makes it worse as Uranus would no longer be a planet as it is profoundly likely that the planet titled because some large body smacked into it.
Furthermore, Mercury almost certainty didn’t clear its neighborhood, the sun did.
The whole point is the third requirement is stupid in that:
1) it, if applied literally, calls into question over half the planets of the solar system.
2) it tells us nothing about the object itself, but the greater context the object find itself in. (i.e. it is absolutely conceivable that a Pluto-like planet could exist between say Mercury and Venus and thus be a planet, or conversely a binary planet system of two Jupiters in a balanced orbit but would not be planets.)
3) the definition is virtually impossible to apply outside the solar system because it is virtually impossible to detect cleared neighborhoods around other stars.
This is why I don’t think it was done because of science! the definition is so stupid, so unwieldy and so useless it seems almost crafted to do one thing and one thing only: strip Pluto out of the family. It raises questions about why the IAU was motivated to do so. It strikes me as profoundly political especially as there is no god damn reason why Eris couldn’t have been recognized as a planet, given that it is one.
@monad
Titan and Ganymede are bigger than Mercury. Furthermore, there almost certainly bigger satellites in other systems.
@34 Azkyroth
That’s no really true. 2006 was when the concept was formalized in a top-down approach in a political charged time of international upheaval by only one relevant body. it’s not like you couldn’t look up the word planet in a dictionary prior to 2006 nor is it the case that the IAU is the only relevant definition.
@michael:
I spoke too loosely; Mercury has a smaller radius than Ganymede and Titan, but is a great deal more massive.
For the rest of what you say, I just linked the formal definition of clearing a neighborhood. If you think it doesn’t clearly apply to some objects and not others, you need to re-read that link. Note too most planets outside our solar system have been detected because they have cleared orbits; if it wasn’t the only large mass in its region it wouldn’t create a wobble.
The third criterion doesn’t actually call into question any of the eight major planets. It does depend on the context the objects are in, but the definition of planet always did; that is the reason objects like Ganymede, Titan, Triton, and Ceres were excluded. Triton may actually be a captured plutoid. Ceres was first considered a planet, then demoted when it turned out to be just one object in a belt. That’s what happened to Pluto now; it has nothing to do with being one of the many, many planets discovered by Americans (most around other stars).
Plait is missing the importance of context, but to some extent he’s right, the definition doesn’t matter and you could as well have eight planets or many. But much of this debate has come from obscuring how the solar system is built, the difference between the massive objects that gravitationally dominate their regions and the smaller ones that occur together as satellites, asteroids, in the Kuiper belt and beyond.
If insisting Pluto and Eris are planets comes with ignoring the ways they are different from the others and similar to other small objects like Ceres and Triton, then it will end up mattering.
But since that object, whatever it was, is no longer present… it leaves Uranus as the gravitationally dominant object at that distance.
And as a result of the process, however it occurred, it left Mercury as the gravitationally dominant object at that orbital distance.
No it doesn’t.
Kinda, but why is it bad to classify something based on the orbital mechanics operating in its vicinity?
It’s actually really straightforward in application. If we detect an object orbiting a star with no other clutter at that orbital distance, then it is a planet. If we detect other objects along with it, it’s a dwarf planet in a belt similar to the asteroid belt. Big deal.
WHAT politics?
And if they had not been captured by much larger objects, they could have been gravitationally dominant and hence planets… but they were, so they aren’t.
Politics? Upheaval?? What on earth are you talking about? Oh and by the way, when it comes to astronomical nomenclature, the IAU is the only relevant body, and no, conversational use of the word ‘planet’ does not qualify as a scientific definition. There was zero scientific definition, then the discovery of Eris (I think) precipitated the debate. That’s all there is to it.
Nerd of Redhead, you are probably thinking of the signals from Voyager.
Some Beautiful high ice Mountains. If the moon had had Mountains like that intead of drab mounds, the space program would not have stalled by lack of public interest in the seventies.
(why the hell is my computer changing letters into caps? Mi-go influence?)
Mercury: 5% of Earth’s mass
The moon: 1.23 % of Earh’s mass
Pluto: 0.3 % of Earth’s mass. Most of it ice.
There may be icy Worlds out there with a mass compareable to inner planets, but Pluto is much smaller.
“some beautiful high ice mountains”
…of madness?
No, I simply misread/misremembered the information in the article I read. Which was earlier in the day. This has been a hectic week.
Just watched last night’s Nova episode of Chasing Pluto. They had the photo’s I linked to at JPL above. Not bad, just a couple of hours from receipt until televised nationally on a science program. Technology can be wonderful.
Not really, chuck Pluto in between Mercury and Venus and you will end up with a very dramatic comet. Unless you mean something just the size of Pluto? Because Pluto is mostly ice as well as being tiny.
Video of New Horizons calling “MOM” (mission operations manager).
http://www.space.com/29951-new-horizons-calls-mom-after-pluto-fly-by-nominal-flight-video.html
The good word of space flight is “nominal”.