It does seem pointless to avoid naming a new era for dramatic irreversible changes that would have defined a new era if they happened millions of years ago.<p>How many common assumptions about the Holocene are already broken?<p>--<p>With much less at stake, I think it was out of touch and impractical to choose scientific terminology at odds with existing common language, when "dwarf planet" was defined as <i>not</i> a subcategory of "planet".<p>It defies common usage, and also common language forms. Prefixed nouns usually refer to subcategories, not excluded categories.<p>What science fiction story is going to carefully distinguish "dwarf planets" as being a completely separate category from "planets" because one didn't completely clear its orbit of debris?<p>A better (equivalent, and just as useful) nomenclature would have left the common definition of "planet" alone: i.e. a body circling a star, too small to be a star or brown dwarf (no continuous or aborted fusion), but large enough to form a near sphere based on its own gravitational field.<p>THEN, subdivide "planets" into "major planets" and "minor planets". We have 8 major planets, and it turns out, many many dwarf planets.<p>Pluto is a "planet", specifically a "dwarf planet". Earth and Jupiter are "planets", specifically "major planets".<p>"Rogue planets" are "planets" that left their systems. Some were originally major, some dwarf. "Protoplanets" are new "planets" actively accumulating mass by clearing their orbital field. They may stabilize as "major" or "dwarf" planets.<p>The new exlusionary definition of "planet" also opens the doors to inevitable conundrums:<p>Some day a huge planetary type body will be discovered in the outreaches of a solar system where it has not cleared its area of debris. So not a "planet"?<p>Some day a small planetary body with a cleared orbital field will be found between the orbits of larger planetary bodies that haven't cleared their fields. So it is a planet, but the larger bodies surrounding it are not?