It’s Official: Pluto is no Longer a Planet August 24, 2006Posted by marvinx in Science and Technology.
Striking down a proposal to add three new planets to the solar system, the International Astronomical Union in Prague announced recently that Pluto is not, in fact, a planet. Thus, there are now eight planets in the solar system: Murcury, Venus, Earth, Mars, Jupiter, Saturn, Neptune… and that’s it.
Where does this leave poor Pluto? It’s been classified along with three other space rocks as a “dwarf planet.” The others are the three which didn’t make the cut for real planethood: Ceres, out in the asteroid belt; Charon, formerly considered Pluto’s moon; and 2003 UB313, an object larger than Pluto and (on average) about three times the distance from the sun (you can learn more about this odd dwarf here).
Of course, the astronomy books will need to be rewritten. Any book you own about the solar system which is newer than 1930 (the year Pluto was discovered) is now officially out of date. School books are a concern: given that schools usually keep books for 5-7 years (or longer), it will be a significant amount of time before this begins to propagate through the system.
The digital world is another matter, though; Wikipedia has already removed Pluto from its list of planets in the solar system and added a highly in-depth explanation of the Astronomical Union’s redefinition of a planet.
There is a possibility, however slim, that this decision will be overturned later; but for now, brace yourself for the cold hard reality: as of today, all those cool mnemonic aids you used to remember the planets in grade school are lies.