Pluto Spanked
Bad Dog.
What does this mean? Probably nothing. Pluto's still there. As well as its three (count 'em, three) moons.
What disqualified Pluto? It's round due to its own gravity, and it orbits the sun primarily, but because it crosses inside Neptune's path for about 6% of its own it doesn't meet the caveat that it has "cleared its orbit of other objects". I presume this doesn't include moons, because then every planet that's not Venus or Mercury would be in trouble (please correct me if either of those planets has a moon I'm forgetting).
What the hell? Doesn't that mean Neptune's not a planet either, since Pluto obstructs into its orbit?
Then there's Ceres. Ceres? Ceres. I hadn't heard of it either until aremisasling mentioned it back when it seemed like we'd have 53 or so planets thanks to earlier drafts of this definition. While Pluto was only recently demoted, this fate had befallen Ceres 150 years ago -- a half-century after its discovery.
Well, shit, that makes sense, right? Ceres, unlike Pluto, shares 100% of its orbit (I think) with lots of other, smaller objects that also principally orbit the sun. Its mass is 1/3 of the entire asteroid belt (hardly a majority) so that's even more damning.
It seems like the rules were created and interpreted to specifically exclude Pluto. I don't think it matters that there are bigger objects out there, especially since they aren't entirely alone in their orbits. I know that this modeling is convenient for our particular, relatively orderly solar system, but we're discovering planets (only gaseous ones so far) around nearby stars -- you'd think we'd be a little more open-minded about irregular orbits, especially relatively inconsequential ones. There are MUCH crazier orbits out there, and there's no denying these huge things are planets...
What the hell ever happened to Sedna, anyway?
[Addendum]
Upon Further Reflection (I swear that's not a Sun joke)...
There are some inanities to the current definition of planet:
-Dwarf Planets -- like Ceres, Pluto, Xena, Sedna, et al have become -- are not planets, even though they have "planet" in the name. WTF? What was wrong with planetoid? Or does that mean something else?
-The third part of the definition of planet, which is what damned Pluto and others, states that the orbit needs to be "clear". The definition is very ambiguous. Clear of what? Objects as large or nearly as large as itself? Jupiter, according to the article, has many asteroids "in lockstep" with its orbit -- hardly clear. Let's not forget all those orbiting satellites in its mini-solar system there. There are plenty of asteroids and comets hovering about Earth as well.
Remember when I said one of the rules was geared specifically to demote Pluto as a planet? This was the one. It presupposes that the space around "proper" planets is pretty much empty, which is far from the truth. And like I said earlier, other planets in other systems have highly irregular orbits.
I really don't care if Pluto is officially a planet or not, but if the bias against that status is going to produce this kind of reasoning, then I think that reasoning needs to be re-examined. If they come up with a definition that isn't so mystifyingly stupid on some counts and Pluto's still not a planet? Fine. At least keep politics out of it (HA!).
~Sean
What does this mean? Probably nothing. Pluto's still there. As well as its three (count 'em, three) moons.
What disqualified Pluto? It's round due to its own gravity, and it orbits the sun primarily, but because it crosses inside Neptune's path for about 6% of its own it doesn't meet the caveat that it has "cleared its orbit of other objects". I presume this doesn't include moons, because then every planet that's not Venus or Mercury would be in trouble (please correct me if either of those planets has a moon I'm forgetting).
What the hell? Doesn't that mean Neptune's not a planet either, since Pluto obstructs into its orbit?
Then there's Ceres. Ceres? Ceres. I hadn't heard of it either until aremisasling mentioned it back when it seemed like we'd have 53 or so planets thanks to earlier drafts of this definition. While Pluto was only recently demoted, this fate had befallen Ceres 150 years ago -- a half-century after its discovery.
Well, shit, that makes sense, right? Ceres, unlike Pluto, shares 100% of its orbit (I think) with lots of other, smaller objects that also principally orbit the sun. Its mass is 1/3 of the entire asteroid belt (hardly a majority) so that's even more damning.
It seems like the rules were created and interpreted to specifically exclude Pluto. I don't think it matters that there are bigger objects out there, especially since they aren't entirely alone in their orbits. I know that this modeling is convenient for our particular, relatively orderly solar system, but we're discovering planets (only gaseous ones so far) around nearby stars -- you'd think we'd be a little more open-minded about irregular orbits, especially relatively inconsequential ones. There are MUCH crazier orbits out there, and there's no denying these huge things are planets...
What the hell ever happened to Sedna, anyway?
[Addendum]
Upon Further Reflection (I swear that's not a Sun joke)...
There are some inanities to the current definition of planet:
-Dwarf Planets -- like Ceres, Pluto, Xena, Sedna, et al have become -- are not planets, even though they have "planet" in the name. WTF? What was wrong with planetoid? Or does that mean something else?
-The third part of the definition of planet, which is what damned Pluto and others, states that the orbit needs to be "clear". The definition is very ambiguous. Clear of what? Objects as large or nearly as large as itself? Jupiter, according to the article, has many asteroids "in lockstep" with its orbit -- hardly clear. Let's not forget all those orbiting satellites in its mini-solar system there. There are plenty of asteroids and comets hovering about Earth as well.
Remember when I said one of the rules was geared specifically to demote Pluto as a planet? This was the one. It presupposes that the space around "proper" planets is pretty much empty, which is far from the truth. And like I said earlier, other planets in other systems have highly irregular orbits.
I really don't care if Pluto is officially a planet or not, but if the bias against that status is going to produce this kind of reasoning, then I think that reasoning needs to be re-examined. If they come up with a definition that isn't so mystifyingly stupid on some counts and Pluto's still not a planet? Fine. At least keep politics out of it (HA!).
~Sean