Not every lifetime has the privilege of experiencing the discovery of new planets â?? in particular in our own solar system. But we are now living in an exiting time. Today a major decision will be made that will effect our solar system. We are going to remove some planets from the solar system.
So how many planets will there be in the solar system tomorrow? If you are a betting person then the safe money is on the number eight. This means that Pluto is out. Even though it has been accepted as a planet since its discovery in 1840 1930.
The reason (New Scientist) for the loss of Pluto is the acceptance of a new planetary definition that a planet must be the dominant body in its orbital zone, clearing out any little neighbours. Pluto does not qualify because its orbit crosses that of the vastly larger Neptune.
Pluto may become either a “dwarf-planet” or planetoid. But even though the safe money is on the adoption of the new definition there is always the chance that the long shot will win and the pro-Pluto-as-planet lobby will succeed! Ok so I have no idea whether there is a pro-Pluto-as-planet lobby but can you picture the whole decision making body: the politics, the lobbying, the intrigueâ?¦ Being an astronomer must be exiting stuff right now.
Or maybe the whole thing is a ruse to be able to reprint all the astronomy booksâ?¦
Take a look at the cool BBC astronomy website.