Thursday, August 24, 2006

The day we lost Pluto

or (And your little dog, Goofy, too!)

It’s official, the International Astronomical Union (IAU), founded in 1919, has defined (I never had that much time in my life to define something -- most of my identify and define tests were given in the time frame of 40 minutes, slackers.) what a planet is:

A planet is a celestial body that (a) is in orbit around the Sun, (b) has
sufficient mass for its self-gravity to overcome rigid body forces so that it
assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the
neighborhood around its orbit.

According to this definition, Pluto has been demoted from a planet to a dwarf planet.
A dwarf planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Pluto is a dwarf planet by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects. All other objects orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".

This definition was hammered out during two meetings of the IAU, after which Jay Pasachoff of
Williams College, was quoted as saying, "I think that today can go down as 'the day we lost Pluto' ".

Does that mean we're going to lose Goofy, too?


http://edition.cnn.com/2006/TECH/space/08/24/pluto.ap/index.html

1 comment:

Terrence Ryan said...

I now have a hydrostatically equalized hole in my heart.