Well, Carlie, the people of NASA are thinking and debating about weather or not it should be one. And I still think it has a chance to become a planet, it might be small but it still orbits around a star (the sun), it has a moon, and has a body. So it has some of the things needed to be a planet, the only reason the kicked it out was because they though of it as to small.
Yes they do have requirements, and I am not sure if this is all of them but these are the ones I know.
-It must be an object which independently orbits the Sun -It must have enough mass so that gravity pulls it into a roughly speroidal shape -It must be large enough to "dominate" its orbit (ie. its mass must be much larger than anything else which crosses its orbit
As we learn more about the universe and about our own solar system, it becomes more and more clear that these human labels which we try to apply to celestial bodies simply don't work. The classifications for something to be a planet or a moon are, in the end, based upon some fairly ancient assumptions about planet and planetary system development. Take, for example, Saturn's rings. We might call them rings but for all practical purposes they are moons of Saturn that are orbiting the planet. We don't call them moons because they look like rings to us, but in this situation neither label applies very well normatively. Pluto has always had a very erratic orbit and so it's motion away from the sun isn't all that surprising. While the Kuiper Belt does have a lot of object in them, it is pulling from all directions on the motion of the planets, so there isn't really going to be a net effect on the motion of the planets. Odds are, Pluto has been in this type of spiraling motion for quite a while and, just like Earth's moon, will slowly release itself from it's major gravitational influence. This whole situation really just serves to demonstrate how incredibly weak the force of gravity is at long distances; it is also important to note that physicists still don't understand what gravity really is or why it even exists!
Okat, your right on that Moe. But Ninjacube, they do know gravity works, if they didnt then they wouldnt knew the gravity ever existed. And gravity it a fact of life. It is a way in space that people do not know that much about.
I'm just afraid that's not the case anymore, Ninjacube. When mathematicians realized that Newtonian gravitation doesn't work at a singularity, it was Einstein's special relativity that solved this problem. Now, quantum physics is used to help explain fundamental principles and reach a unified theory that explains all forces, including gravity. Currently, physicists posit little things called gravitons that have not been observed in any way but are used to explain "gravitational fields" which don't really exist either. Hooray for making things up as you go along!!
Well I don't study Astronomy so I don't know much about this but I will say that Pluto is the coldest planet and maybe its going to something cold and all cold planets go there and hot planets come towards the sun!
Yea but if they never came up with that then how did they know gravity was out there. Was it all just luck? No, it WAS Newton that found it out. So, if he didn't have the apple drop oon his head, then we would have never known what gravoty is.
KoS, that has nothing to do with anything. Cold planets do not go were cold planets go (which in this case is the Kuiper Belt) and warm planets do not go towards to sun. And the sun goes to the planets.
As the sun ages, it expands, getting bigger. And right now, it is at a main sequence star. But it a couple milion years, the sun will expand so much that it will engulf Mercury, Venus, Earth, and Mars.
The idea of gravity was well know before Newton came along, he just developed what were (at the time) universal formulas for explaining the movements of objects through space. Also, the apple story is just some cute little story that has no bit of truth. I mean really, do you think Newton was the first person to notice that apples fall from trees? Until Newton's laws of motion we operated using Aristotle's ideas of telos to explain an object's motion. Things falling and moving through space have been observed for thousands of years and this motion has been given several names. Certainly we are closer to understanding motion that Aristotle was but we still don't understand why gravity needs to exist from the standpoint of physics.
Well I was just guessing I said I was bad at Astronomy but I guess it might and I hope it does!And I suppose it should be a dwarf planet because its tiny!
It shouldn't just a be dwarf because it is tiny, it should be a planet. It orbits around a star(our sun), it is a sphere, it has a moon, and it has a atmosphere and a surface, crust, mantle, and core. It has almost all it needs to become a planet.
Okay, but here are the criteria for a dwarf planet (taken from wikipedia, I think).
1. is in orbit around the Sun, 2. has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, 3. has not cleared the neighbourhood around its orbit, 4. is not a satellite.
So the major difference here appears to be a clear orbit. I don't know if Neptune is considered to be the invading celestial object, or if they other Kuiper Belt objects are considered to be in its path. I don't like this designation of a dwarf planet, though, either because what's to stop the several million other Kuiper Belt objects from being designated as "dwarf planets"?
