Just as in the Bible Adam achieved dominion
over the objects of the earth by naming them, so scientists partly
establish human dominion over the cosmos by naming or classifying
all things animal, vegetable, or mineral.
At a meeting of the
International Astronomical Union (IAU) last week in Prague, the
system of naming planets was revised, and not everyone was pleased.
Hereafter, they declared, there will be eight proper planets and at
least three (and probably lots more) dwarf planets. To be a planet
an object must be orbiting the sun, must be spherical, and must be
big enough to have scarfed up all the matter in its orbital zone.
Pluto, having failed the third of these criteria, is now demoted to
being a dwarf planet, and is joined in that category by two other
objects, Ceres and Xena (whose official name is still 2003UB).