re: A matter of size and choices
I heard Patrick Moore in his latest Sky at Night program say it's obvious Pluto can't be considered a planet anymore.
It's a fascinating debate because it goes further than the astronomers circles.
It's interesting because it's also political: an english astronomer discovered Uranus, a french astronomer showed where Neptune would be and was right and an american astronomer discovered pluto (the name chosen by an english girl).
The french accepted the meridian would cross Greenwich rather than Paris, provided the english would turn to the metric system...We're still waiting....Would it take as long to demote Pluto? ;))