2006-12-28 14:27:02 · 10 answers · asked by Archie F 1 in Science & Mathematics ➔ Astronomy & Space
Charon. When Pluto is refered to it is sometimes refered to as Pluto-Charon because charon is Pluto's moon. The moon is almost as big as Pluto, that is why it is sometimes refered to as Charon.
2006-12-28 14:33:05 · answer #1 · answered by Rosie 1 · 0⤊ 1⤋
Since the IAU decision of 24 August 2006 we only have 8 planets, There are 3 dwarf planets: Eris, Pluto and Ceres,
The IAU has another dozen or so candidates for dwarf planets, one of which is Sedna, but is postponing a decision till it has more information about them to hand.
Misinformation about Sedna continues to circulate and be uncritically repeated here on Yahoo Answers.
The nearest it ever gets to the Sun (its perihelion) is 75 AU (the earth is 1 AU from the Sun), And at its furthest away (its aphelion) it is as far away as 975 AU, which is in the region of the Oort Cloud.
It takes 12,050 years to complete one orbit of the Sun. Not 200 million years or anything like it! (200 million years is the time it takes for the solar system to complete one orbit within the Milky Way!)
None of that necessarily prevents it being accepted as a planet. However it is smaller than Pluto. Even Eris, which is bigger than Pluto, was not accepted as a planet at the recent IAU congress in Prague, so it must be probable that the most Sedna can hope for is eventual acceptance as a dwarf planet,
The likelihood is that a ninth planet would need to be at least as big as Mercury to stand any chance of being accepted as a planet. And we know of no such objects at present. They would need to be out beyond Pluto and as yet undiscovered as we can be reasonably confident that anytning inside the orbit of Neptune of that size would have been noticed by now, not least because of its gravitational infuence on other planets.
Ganymede and Titan, the largest moons of Jupiter and Saturn respectively are in fact both bigger than Mercury, But they orbit planets not the Sun and a planet needs (by definirion) to orbit a star.
2006-12-28 16:45:51 · answer #2 · answered by brucebirchall 7 · 0⤊ 0⤋
There is no longer a 9th planet. According to the IAU there are 8 and only 8 planets. However in my mind, pluto will always be the 9th planet.
2006-12-29 04:10:31 · answer #3 · answered by May M 3 · 0⤊ 0⤋
They say it's Sedna which takes approximately 200 million years to to go around the Sun. I don't think they should considerf it a planet because of how long it takes to orbit. I mean Pluto WAS cutting it close as it was. Go take a nap because it don't matter.Pluto isn't a planet anymore anyway.
2006-12-28 14:34:33 · answer #4 · answered by karatechamp2007 1 · 0⤊ 1⤋
Well, it's all up in the air right now. (No pun intended)
Since Pluto has lost it's designation and larger bodies have been discovered it's difficult to get everyone in agreement. But Sedna and Xena have been issued tentatively to the largest objects in or near the Kuiper Belt.
2006-12-28 14:34:42 · answer #5 · answered by Awesome Bill 7 · 0⤊ 0⤋
It is past Pluto and they tried to demote Pluto to a moon. It is pretty much figured out mathematically that there is a pull on other planets.
2006-12-28 14:30:42 · answer #6 · answered by Anonymous · 0⤊ 1⤋
There are only 8 official planets now.
2006-12-28 14:32:01 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Pluto is and will always be the ninth planet. I know this in my heart and no one can take it away from me. You hear me?
NO ONE!!!
2006-12-28 14:29:27 · answer #8 · answered by Anonymous · 0⤊ 1⤋
It's called Sedna. I got a good website for you to visit about it. go to...
http://en.wikipedia.org/wiki/90377_Sedna
This gives you all the info you need. It also gives you pictures, diagrams, stats, and a whole lot more. Hope this helps.
2006-12-28 15:54:18 · answer #9 · answered by Anonymous · 0⤊ 1⤋
there isnt one
2006-12-28 14:29:39 · answer #10 · answered by Dashes 6 · 0⤊ 0⤋