Already there.
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Sorta my point…Saturn is closer to an ellipsoid, further from a sphere, and so far as I know there’s no official standard which matters more. I have heard “round” referenced a lot in these discussions but unlike Λ, which sharply distinguishes the eight largest masses around the sun from all the others, I’ve never seen it actually defined in a usable way.
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Well then rather than deviations from true sphericity I would propose smoothness, taken as the ratio of maximum deviation of the surface to the ellipsoidal mean radius.
Has it really been 18 years? Damn, feels like yesterday, and you know what they say, you always remember where you were when a planet gets demoted to “dwarf planet.” I assume they say that, anyways.
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They Might be Gas Giants!
OK, maybe their concerts should only be in open air…
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Hey Pluto and Charon, be what you want to be! Don’t listen to what anyone says, just do you!
Not that it should matter, but you’ve got my vote!
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A potato factor, perhaps. Where Saturn despite its deviancy has a low potato factor but Phobos has a rather high potato factor.
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I’m glad that they decide to cut off Pluto. If they hadn’t, we’d be hearing every couple of weeks that scientists had found yet another really large object beyond Makemake. They changed the definition, and now we don’t have to care.
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If you don’t care now, you wouldn’t have cared anyway and all it would have done is make the other planets seem dime-a-dozen too. But making taxonomy about advertising is a profoundly bad decision either way. It’s supposed to be a framework people can build on for understanding, not a weird trick to get more clicks.
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In my opinion this was always the dumbest rationale for coming up with a new exclusionary definition for “planet.” Say that did mean we had a bunch more planets in the solar system than the eight or nine everybody knew—so what? That’s how discovery works. There are a lot more moons in the solar system than we used to know about too but everyone eventually learned to deal with them.
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I mean, that’s exactly what people did with asteroids – they realized they were a group of many smaller objects and so stopped calling them planets. And there actually could be a problem having too many planets for the IAU, since they don’t get numbers and everything like other objects do. But I was just saying that it’s stupid to go the other way too, and think we have to call things planets for PR purposes, a real argument jerwin was alluding to.
There is the recurrent idea in all this that terminology should be designed based on what the (usually American) public likes instead of what the solar system looks like. I am against all of it. Pluto itself doesn’t actually want to be a planet, and science works best trying to find relatively natural categories.
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There are likely quintillions or sextillions of planets in the universe. Pretty sure the IAU was never going to come up with enough names for all of them anyway.
(Excepting the actual planet Sextillion of course. That’s just solid branding.)
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Back in 2006:
On Wednesday, August 16, 2006, the International Astronomical Union (IAU) announced a proposed definition of a planet. A significantly revised version of this definition was passed by the membership at its general meeting on August 24, 2006. The IAU is an international organization of over 8,000 astronomers representing over 80 countries and held its meeting this year in Prague. The proposal for defining “what is a planet” and the fate of Pluto has been making front-page news for several weeks. In the draft resolution, three “planets” (asteroid Ceres, distant object 2003 UB313, and Pluto’s satellite Charon) were added to the existing nine planets. However, there was concern by many astronomers that, if this definition of a planet passed, there was the likelihood that dozens of other planets would be added in the near future.
https://dps.aas.org/education/what_is_a_planet/
It’s somewhat ironic that this likelihood didn’t come to pass.
Gonggong (dwarf planet) - Wikipedia looks to be the latest such large object, discovered in 2007.
It’s a shame. I would have liked to have seen which minor planets got named after Cloacina or Priapus.
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The IAU haven’t decided on a lot of them
Including this one
I don’t think that was going to make it into British or American classrooms.
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I have a 7th grade science fair project made out of 9 styrofoam balls that says otherwise.
It also got a D so what do I know.
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there is a sort of symmetry between objects that are massive enough to be round, and objects that are massive enough to start stellar fusion.
The problem is that you couldn’ define the roundness criterion rigorously enough, so they settled on the theoretical clearing of the orbit, given infinite time, and in the absence of interesting interactions like this.
here, of course, the 4 smallest planets are so gravitationally weak that they can safely ignored.
