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Pluto update
Aug. 23rd, 2006 12:22 pm
According to the latest news it looks like Pluto may be denied planet status after all. Rah!
One of these things is not like the others:
Give Pluto the boot!
Aug. 20th, 2006 10:31 amCheck out this list of solar system object by mass.
The Sun is by far the most massive object in the solar system, making up over 98% of the mass of the entire system. After that come the planets, starting of course with Jupiter, and finishing with Mercury. Then there's seven of the larger satellites: Ganymede, Titan, Calliso, Io, the Moon, Europa, and Triton. After that comes the newly-discovered trans-Neptunian object, 2003 UB 313, better known as "Xena".
After all that, you get Pluto. Less than one-twentyfifth of the mass of the next-smallest official planet, Mercury. Its orbit is so weird it crosses the orbit of Neptune for years at a time, and it's not in the ecliptic plane. Its likely composition: a big lump of cold rock.
It only barged its way into the planetary club because the presence of its moon Charon caused astronomers to believe that Pluto was much larger than it turned out to be. In fact Charon is practically as big as it is, with the result that rather than one orbiting the other, it makes more sense to describe it as a binary system, with both orbiting a single point in space, faces locked towards each other.
If Pluto is allowed to stay in the club, we'll have to allow in all sorts of dull riff-raff - not only Xena, but Ceres, Charon, and possibly others like Quaoar and Sedna. No-one will be able to remember the names of all the planets.
I implore the IAU to strip Pluto of planet status as soon as possible. It should count itself lucky that we allow it to stay in the solar system at all.
The Sun is by far the most massive object in the solar system, making up over 98% of the mass of the entire system. After that come the planets, starting of course with Jupiter, and finishing with Mercury. Then there's seven of the larger satellites: Ganymede, Titan, Calliso, Io, the Moon, Europa, and Triton. After that comes the newly-discovered trans-Neptunian object, 2003 UB 313, better known as "Xena".
After all that, you get Pluto. Less than one-twentyfifth of the mass of the next-smallest official planet, Mercury. Its orbit is so weird it crosses the orbit of Neptune for years at a time, and it's not in the ecliptic plane. Its likely composition: a big lump of cold rock.
It only barged its way into the planetary club because the presence of its moon Charon caused astronomers to believe that Pluto was much larger than it turned out to be. In fact Charon is practically as big as it is, with the result that rather than one orbiting the other, it makes more sense to describe it as a binary system, with both orbiting a single point in space, faces locked towards each other.
If Pluto is allowed to stay in the club, we'll have to allow in all sorts of dull riff-raff - not only Xena, but Ceres, Charon, and possibly others like Quaoar and Sedna. No-one will be able to remember the names of all the planets.
I implore the IAU to strip Pluto of planet status as soon as possible. It should count itself lucky that we allow it to stay in the solar system at all.
