Yes that's interesting, Pluto was only discovered in 1930, and then recently down graded to status of Dwarf planet. Other objects have been discovered and are larger than Pluto, but not yet given planet status as far as I know.
Pluto is scorpio's ruler or co ruler with Mars? I know very little about astrology must admit, but always intrigued how Pluto retrograde seems to affect me so much.
Is Mars more important to Scorpio than Pluto, I wonder. Certainly been affected by Mars retrograde career wise this year. You raise a good point, and one that I had not thought about before. What do you think?