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IAU Proposes 3 New Planets
IZ Reloaded writes "Sources tell SPACE.com that the International Astronomical Union is preparing to include three new entries to the current list of planets in our solar system. From the article: The asteroid Ceres, which is round, would be recast as a dwarf planet in the new scheme. Pluto would remain a planet and its moon Charon would be reclassified as a planet. Both would be called "plutons," however, to distinguish them from the eight "classical" planets. A far-out Pluto-sized object known as 2003 UB313 would also be called a pluton."
How long until we can get Cowboy Neal reclassified as a pluton?
liqbase
Here are the three additions:
*The asteroid Ceres, which is round, would be recast as a dwarf planet in the new scheme.
*Pluto would remain a planet and its moon Charon would be reclassified as a planet. Both would be called "plutons," however, to distinguish them from the eight "classical" planets.
*A far-out Pluto-sized object known as 2003 UB313 would also be called a pluton.
Information wants a fueled airplane waiting at the hangar and no one gets hurt.
Pluton politely asks media corporation not to use His name as a generic noun.
Charon differs from Luna because Pluto and Charon jointly orbit around a point outside either of their bodies, whereas Luna orbits a point inside the Earth. Pluto and Charon are therefore (currently) technically a twin planet system.
The way I teach it in my classes is that there are 4 inner planets, 4 outer planets, and a (large) set of Kuiper Belt objects, of which Pluto is one of the largest and closest members. Why do we need a planetary definition? Historically, any serious attempt to classify natural objects eventually runs into problems anyway, especially when our first attempt includes objects that obviously belong to a number of sub-classes, each of which contains a continuum of members.
Somewhere, Space Fonzie is jumping over an Astro-Shark.
Slashdot Burying Stories About Slashdot Media Owned
Planet: A celestial object orbiting a star that is massive enough for its own gravity to warp itself into a nearly round, spherical shape. A planet may not be massive enough to initiate thermonuclear fusion. In order for a pair of celestial objects to be considered a double planet, in addition to meeting the forementioned criteria, the barycenter of both objects must be located above their surfaces. Planetary systems orbit a barycenter, or their center of mass. Usually that center of mass is located at the center of the planet, but in the case of Pluto, the gravity of its "moons" pull the barycenter above the surface. As a result, Pluto is perpetually orbiting the center of mass of the planetary system, as illustrated in a chart located in the Wikipedia article. This is why Charon and Pluto are being considered double planets. I think that's the best set of criteria that can be offered. Why is the idea of over 50 planets so abhorent? Why must size and the number of planets be decided arbitrarily? We might as well use Isaac Asimov's mesoplanet suggestion, in which all objects with radii between Ceres and Mercury are mesoplanets, if this is how it is to be decided.
That's already how Pluto is spelled in French. I guess we could refer to small-p plutons for Pluto, Charon and Kuyper objects. And of course 'Pluton', being the eponymous pluton.
....what do they smell like?
Fry: Did you build the Smellescope?
Farnsworth: No, I remembered that I'd built one last year. Go ahead, try it. You'll find that every heavenly body has its own particular scent. Here, I'll point it at Jupiter.
[Fry sniffs.]
Fry: Smells like strawberries.
Farnsworth: Exactly! And now Saturn.
[Fry sniffs.]
Fry: Pine needles. Oh, man, this is great! Hey, as long as you don't make me smell Uranus.
[Fry laughs.]
Leela: I don't get it.
Farnsworth: I'm sorry, Fry, but astronomers renamed Uranus in 2620 to end that stupid joke once and for all.
Fry: Oh. What's it called now?
Farnsworth: Urectum. Here, let me locate it for you.
It's a b... I mean, it's actually part of a double-planet system, orbiting around a common point in space (unlike all other moons in our solar system). And Ceres is an asteroid with a name, thank you very much.
In answer to your second question, since August 24, if the vote passes.
Why would anyone engrave "Elbereth"?
(Nor a space station)
It's not orbiting Pluto, but instead a point between itself and Pluto. If the mass of Pluto was higher, so that their common center of gravity was inside pluto, then Chauron whould indeed be a moon.
FRA: STFU GTFO
This sig seemed like a good idea at the time....
Let's see the good side of things, maybe Ceres with its new status will gain some more interest, *maybe* even enough for it to have the honour to be probed by us. Would surprise me a bit tho.
Edit : seems that there's already a probe destinated to Ceres (among others) nammed Dawn
Edit #2 : yeah I know, you can't actually edit your posts
You just got troll'd!
The whole difference between a "planet" and a "moon" is a fallacy. It assumes things can orbit only a physical object, and not an immaterial object like a center of mass. The "official" definition fails not only in the obvious Pluton-Charon case, but even for Sun-Jupiter (putting the smaller bodies aside for now). We orbit not the Sun, but the center of mass of the Solar system, which is actually outside the Sun itself.
...)
Thus, with the difference between "planets" and "moons" away, the classification that matters is:
* pieces of rock (Mercury, Venus, Earth, Moon, Mars, Phobos, Deimos, Europa,
* sub-stellar balls of gas (Jupiter, Saturn, Neptune, Uranus)
* pieces of dirty ice
And to make it even harder, there is absolutely no reasonable boundary between "almost big enough to fuse" and "one particle". The difference between a "pebble" and a "boulder" isn't tangible.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
I completely disagree with that the current system is better, but I don't see why your question merits the moderation (-1, Troll).
It's completely unsatisfactory to talk about "planets" when we don't know what is meant by a planet. Simply enumerating the ones in our solar system makes it very clear for our system, as we did so far, gives clarity for our solar system: the nine ones are planets, all others aren't. It doesn't state a reason. If asked why Pluto is a planet, and the very similar 2003 UB313 ("Xena") isn't, all we can say is: "historical reasons" or "convention".
When describing other solar systems, it is very normal to describe celestial bodies which are similar to the planets of our solar system, as "planets". But when is a body sufficiently like a planet of our own, to merit this description?
Really, it was high time we got a workable definition. Anything. Anything is better than an enumeration.
So, the International Astronomical Union (IAU) currently holds a highly-anticipated conference on the definition in Prague. It started last Monday, and a final decision is expected by next Thursday August 24, 2006.
The current proposal is:
It has the added benefit that the minimum size (to exclude most Kuiper belt objects etc.) is not an arbitrary number, but a physical condition. The shape of objects with mass above 5 × 10^20 kg and diameter greater than 800 km would normally be determined by self-gravity. In borderline cases, we now must observe the roundness.
The pluton definition does have an arbitrary figure in its proposed definition: orbits around a star that takes longer than 200 years to complete.
It's psychosomatic. You need a lobotomy. I'll get a saw.
Having had both land on me at one point or another in my life, I beg to differ.
The Earth and the Moon also revolve around a common point, which is inside the Earth.
A perspective I've read on this is that our moon's orbit is everywhere concave with respect to the sun. So it's more accurate to interpret the Earth-Luna pair as not really orbiting each other, but rather sharing a solar orbit. Two bodies that are close together in the same orbit do swap places periodically; there are several known cases of this in the Jupiter and Saturn systems. From a rotating frame of reference, they appear to be orbiting each other. But viewed in a static frame, they appear to be swapping the lead periodically. So the Earth-Luna pair could be more accurately considered a binary planet pair in a common orbit.
It's all rather nitpicky anyway. As numerous astronomers have pointed out here, they mostly don't use such vague terms as "planet". And an orbit isn't really a property of the bodies in an orbit; it's a property of the system.
The "debate" is basically a media event, based on people who take their grade-school science classes too seriously, and think that for some reason that the Solar System must contain exactly nine "planets".
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
I thought sub-stellar balls of gas came from Uranus.
Orbjects: noun. contraction of ORBiting oBJECTS (with the repeated B collapsed to a single character). Any object in a solar system that orbits. Focus of such orbit must be another object or center of gravity derived from two or more objects.
Further classification:
Little Orbjects: Wee orbjects that require only a passing flock of waterfowl to achieve escape velocity. Can only contain volcanos, sheep, roses, and possibly a child, tippler, king, or accountant.
Big Orbjects: Orbjects that would require an actual propulsion system including significant amount of reaction mass to achieve escape velocity.
Huge Orbjects: Orbjects whose mass is so great that a human being could not survive its gravitational pull. Or better stated, orbjects that you might have sex with, but wouldn't introduce to your friends.
But according to an article by Isaac Asimov (Just Mooning Around from Of Time and Space and Other Things), the Sun pulls the Moon twice as strongly as the Earth does, and the Moon's orbit, drawn to scale, is always concave toward the Sun, making a very convincing argument that the Earth and the Moon are a double planet system, even though their center of revolution is a thousand miles beneath the Earth's surface.
If Charon is to be classified as a minor planet, the Moon should be too.
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The term "dwarf planet" is actually starting to grow on me. It still keeps Pluto as a planet, for those who absolutely need it to be a planet, but really it IS a demotion to a status equal to the larger asteroids & KBOs. The way I see it, the Solar System has 8 Major Planets (4 terrestrial, 4 gas giants), at least 50 Dwarf Planets (Pluto, Ceres, 2003 UB313, etc) that are round due to self-gravitation, and the non-round objects can still be called Minor Planets. It just adds an intermediate classification between "planet" and "asteroid/minor planet".
The "debate" is basically a media event, based on people who take their grade-school science classes too seriously, and think that for some reason that the Solar System must contain exactly nine "planets".
I think that one of the problems in this country (the US) is that we do not take grade school science seriously enough. We need those science classes to engage the kids and hopefully inspire some of them to a career in some scientific field.
Shouldn't the Sun have a hell of a tide due to Jupiter?
Tidal effects (the difference between gravitational acceleration at the near and far sides of an object) vary with the inverse cube of distance.
/. If the government wants us to respect the law, it should set a better example.
The difference between a "pebble" and a "boulder" isn't tangible.
"Pebble" has a formal scientific definition of small alluvial material from 4 to 64 mm diameter. "Boulders" are more than 256 mm diameter. Assuming the piece is a standard stony material such granite, drop a pebble of granite on your left toe and a boulder of granite on your right. I believe you will quite clearly note tangible, tactile differences. You might also try carrying a boulder in your back pocket and a pebble in a front pocket in your pants, or the other way around, if your are insecure with your girlfriend. Whenever you try sitting I again suspect you will note "tangible" differences.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.