Old debate re-opened - What is a planet?

I must admit I'd prefer Sedna to be a planet, and I agree when Terry says 'planet' should have a diameter of 1000 miles as a lower limit, which I also think has a nice 'round' feel to it

...of course having a planet for each of our digits is hardly a scietific reason behind having Sedna as a planet, but it is a fun one

Have Fun,
Jim.

If nasa weren't to use the diameter as a means of deciding its a planet, what other ways do they have of deciding

gravity ? how spherical is the body ???

I'd also like it to be called a planet, when will they decide ?

A term I have'nt seen for a few years now is "minor planet"
I rmemeber see the bigger asteroids been refered to in this way.

As for what makes a planet ... that is a really difficult question! My definitions would be a large body in an almost circular orbit around a star. Hence I would re-classify Pluto as an EKBO and reduce us to 8 planets.

I like this method and have voted accordingly

voyager wrote:

As for what makes a planet ... that is a really difficult question! My definitions would be a large body in an almost circular orbit around a star. Hence I would re-classify Pluto as an EKBO and reduce us to 8 planets.

would this not mean that you'd have to reclassify some of the largest asteriods and titan and the galilean moons to planets? should a planet not have at least some sort of atmosphere?, or at least the mass to retain one.
stephen.

voyager wrote:

As for what makes a planet ... that is a really difficult question! My definitions would be a large body in an almost circular orbit around a star. Hence I would re-classify Pluto as an EKBO and reduce us to 8 planets.

would this not mean that you'd have to reclassify some of the largest asteriods and titan and the galilean moons to planets? should a planet not have at least some sort of atmosphere?, or at least the mass to retain one.
stephen.

By that logic stephen wouldn't mercury need to be reclassified as well

ladies and gents,
www.space.com/scienceastronomy/sedna_earth_040316.html
there could even be another earth sized planet out there.
stephen.