. . . but it has five moons? Story. Not bad for a dwarf planet or kuiper belt object or whatever Pluto might actually be. New Horizons gets out there in 2015 and I can't wait to have a close-up look at the little bugger.
Technically Pluto has only four moons as Charon really doesn't fit the definition of a moon given Charon and Pluto both orbit a common center of gravity that lies between the surfaces of the two. Properly, you would say that Pluto/Charon has four moons. At any rate, they really twisted the definition of a planet to eliminate Pluto. By insisting that a solar orbiting body could only be a planet if it has "cleared other objects from its neighborhood (or a similar word). Now, there are no other orbiting bodies anywhere near Pluto. But because Pluto follows an extremely excentric orbit around the sun and there are other objects in similar orbits billions of miles further out it was decided that since Pluto has not "cleared" those other bodies out that Pluto is not a planet.
Technically, you're wrong, since the barycentric component of the definition does not actually exist. The IAU officially (and therefore "technically") defines Charon as a satellite of Pluto. In fact, the barycenter of the Pluto/Charon system is so close to Pluto that Charon fully orbits Pluto's orbit. For what it's worth, the Sun and Jupiter have a similar relationship to Pluto and Charon: The Sun and Jupiter each orbit a barycenter that is outside the surface of the Sun. Pluto has NOT "cleared it's neighborhood", and the part I bolded in your quote is in fact flat out false. If you total up the mass of all other objects that SHARE THE SAME ORBIT AS PLUTO, you find that Pluto only represents 0.077 of that mass (also known as Soter's Planetary Discriminant). For reference, the smallest value for that number for one of the eight planets is 24000. Pluto sucks at being a planet.
Once they confirm a few more Kuiper Belt objects as being bigger than Pluto, hopefully all this butthurt over its downgrading to "dwarf planet" will die out.
I bet if Pluto crashed into Neptune, it would do little more than make a long-lasting dark spot on Neptune's outer "surface."
I know, right? .... Does this mean Neptune's technically not a planet, for not having cleared Pluto/Charon out of its orbit? Also, my understanding is that Pluto and Neptune's orbits never intersect each other, as Pluto's orbit is angled to the plane of the ecliptic, so we'll never have anything interesting like Neptune's Plutoic Dark Spot.
That is correct. At perihelion, Pluto gets a shade inside Neptune's orbit, but because Pluto's orbit is at such an angle to the plane of the ecliptic, when it gets near "Neptune's orbit" it is so high above or below it (depending on how you look at it) that they never actually get near each other in 3-dimensional space.
When I was a kid, there were no such things as planets. Oh, yeah, bitches! My dad and I STARTED this universe. He was proud the day I invented gravity.....
Also Pluto and Neptune are in a 3:2 resonance, so they are only in alignment with the sun at a very few well-defined points in their orbits.
Never forget that Ceres was once a planet. I dont think anyone wants that one to come back into the fold
