planet formation

I agree on the 'spherical' bit, but disagree on using mass as the definition. Again, I'd
recommend the link above by Soter on "What is a planet": I think that clearing the orbit,
hard to explain as it is, is the kernel of a good definition.

The aim of the IAU discussion was to move from an arbitrary definition of a planet
(these 9 objects) to a physics-based one. Now that we discover new
Edgeworth-Kuiper Objects and substellar objects (theres a lot of interesting things
happening at the other end of the mass scale, too: the difference between
planets, brown dwarfs and stars), we need a good physics-based definition. We
want to understand and explain the universe, not just categorise it.

If you were to pick a mass based definition, what would you choose (see the edge
cases in Soter, for example).

Regards
Alastair

A "Dwarf Planet" is still a planet.

Dwarf people are still people!

The crass stupidity of this comical affair will rank with "How mant angels can dance on the head of a pin?" which worried previous generations.

Peter.

John Murphy what a clear mind you have It should be interesting to see what Dr Emma Whelan has to say on the matter in the IAS talk on Monday as she is actively working in the field

Deirdre Kelleghan
Irish Astronomical Society
www.irishastrocsoc.org