The problem really is Pluto supporters miss the status that the word “planet” confers. Dwarf planet, Plutino, and minor planet all have connotations of “lesser”.
Let’s leave “planet” as the IAU defines the word and use “world” as a significant place to explore.
Jupiter’s mass would have to increase by at least 7500% to have sufficient mass for stellar fusion.
But a blob of wax is more similar to a candle than it is to a pebble.
I think this is still wrong. Jupiter is like a huge earth (dense metallic/rocky core) plus a huge amount of Hydrogen (and other gases). Jupiter is not just a big ball of gas. It has a lot more in common with Earth than with the Sun, principally the fact that nuclear fusion is impossible.
I read the story yesterday. I was going to wait until the dust settled. Once Pluto was reinstated as a member of the Planet Club, I…
… Yeah, that. I was going to post:
In your face, Neil deGrasse Tyson!
As usual, I’m beaten to the punch.
Why do people get so hung up on whether Pluto is a planet?? There are a million questions/topics in astronomy more interesting and worthwhile to debate than this.
Because it’s one of the few astronomy tidbits that nearly everyone was taught and remembers.
I dunno why but it gets me angry too, there are nine planets dammit!
Get off my lawn!
Regardless of how you compare Jupiter and Sol, it’s still the case that Earth is more like Ceres or Luna than any of those objects is like Jupiter. I’m another proponent of having separate categories for rockballs, iceballs, and gasballs.
Failing that, I’ll settle for “Orbits a star and is big enough to be round”. Note that this includes not only Pluto, but Eris, Sedna, Quaoar, Ceres, and Luna, plus doubtless many others that have yet to be discovered.
Certainly, the IAU’s current definition is absurd, since if applied consistently, it would rule out Earth. We share our orbit with another body large enough to be a planet-- In what sense have we “cleared our orbit”?
I think a planet (besides orbiting a star) should have enough mass to make it spheroid. Whatever definition and limits of spheroid is. But a ball dammit. I think Pluto fits this.
Gotta read Mike Brown’s How I Killed Pluto and Why It Had It Coming, people. He’s not only a brilliant astronomer, responsible for finding enough Kuiper Belt Objects to establish that Pluto is one of them, he’s a marvelously entertaining writer too.
Anyway, make Pluto officially a planet again, and you have to make every asteroid and every KBO and every Oort Cloud pebble one too. There aren’t enough names to go around.
I think “cleared our orbit” doesn’t mean we can’t have moons – it means that there can’t be any significant chunks of matter in or very near our orbit that have not been either captured as a satellite or destroyed/ejected.
So “capturing” a moon is part of clearing our orbit. Just like Jupiter and Saturn have moons which are even larger than our moon.
It’s this absurdity that’s so frustrating. The term ‘planet’ has to have a universal application.
If we were to explore the nearest, say 20 systems, we’d have a good chance of finding an Earth-sized object (let’s call it Orth) orbiting in the “neighbourhood” of a gas giant.
The IAU’s formula would not only rule out Orth as a planet, but possibly the gas giant as well. It’s insane.
I don’t think you guys understand what “cleared our orbit” means, especially considering that the largest moons in the solar system belong to Jupiter and Saturn.
I’m not an astronomer, but this thread seems so full of ignorance. Those of you who feel some people decided they wanted to kick Pluto out and then came up with a reason to do so: it looks more like you want Pluto IN and are trying to come up with reasons to do so.
Pluto is smaller than the Moon. The barycentre of Pluto’s orbit with its own moon, Charon, is not even within Pluto. Pluto can’t even orbit the Sun properly without crossing Neptune’s orbit.
This thread needs more astronomers and space nerds.
What I want to know, is what’s Charon if Pluto’s not a planet?
Poor old Charon, got the status drop, but none of the publicity.
I’m fine with the dwarf planet designation, but I really think that Pluto and it’s associated moon Charon should be designated as a binary planet since the two are virtually equal in size.
If we’re gonna do this, then I hope they keep the naming convention and we Trekkies finally get our own Vulcan!
I would think Vulcan has been permanently blacklisted. Name has already been assigned, although the object to which it was assigned turned out to not exist thanks to Einstein. (IIRC)
Because Pluto is the only planet named after a character you watched on the Saturday morning cartoon shows, on a black-and-white TV in 1964. 