Experts meet to decide Pluto fate, Finally we'll know what a 'planet' is... Options

[MizarKey]

One of many articles regarding the upcoming conference...

Experts meet to decide Pluto fate

[nprev]

Mmm...pickled spicy xylophones....

Interesting take from the IAU on this contentious issue. Ceres, though...looks pretty spherical from the HST images (which Dawn should amply confirm), as does Vesta despite its south polar divot...gotta wonder what Chiron's morpology is , as well as that of other Centaurs, and where to really draw a line that might mean something?

Point here is, obviously, that if this definition is rigorously enforced we may end up with a heckuva lot of planets, and that might get pretty cumbersome very quickly. Why not add a diameter provision (let's say that of Pluto, because it's probably a safe bet that there are many bodies bigger than 2003UB313 further out) as an additional requirement for planetary status? Like everything else in nature, the natural satellites of any star will exhibit a continuum of sizes rather than fall into nice, neat categories...gotta put this fire out now before it spreads.

And actually, let me present a new concept: the "Mercury Standard". Mercury is the smallest universally recognized planet, and its distinctive features with respect to planethood are that it formed independently as the result of accretion from the primordial Solar nebula at or near its present orbit. Using this logic, any body that is smaller than Mercury and in an orbit that exhibits any evidence of prior association with a major planet (the old "escaped moon" chestnut) would be excluded from planetary status. This would presumably eliminate Pluto, but perhaps admit Sedna and 2003UB313 if their respective orbital parameters are "clean".