One of the consequences of the demotion of Pluto from planet to dwarf planet is being felt by astrologers, who now have to decide what role the body plays in the lives of mere humans.
I remember reading an article many years ago wherein the writer asked several astrologers what impact the discovery of a new planet would have on their craft and whether it would render earlier predictions incorrect.
Some argued that horoscopes developed before all nine planets (as there were then) were discovered were inaccurate. As astronomers discover more planets, the predictions of astrologers become more accurate. This position at least strikes me as defensible once you get over the proposition that a hunk of icy rock orbiting at the edge of the known solar system has any influence whatsoever on whether you feel cranky today.
The position I found more baffling was the one that claimed that those old horoscopes were still good, because only after they are discovered do planets begin to influence the lives of humans. Why would a hunk of rock behave differently depending on whether we know it exists or not?
Or maybe their point is that astrology is all about how humans perceive the planets and not the other way around.