Mike Brown on Killing Pluto and Replacing It with Planet 9 (opens in new tab)

Few events in recent astronomical history have had the worldwide emotional resonance as the 2006 announcement that Pluto was no longer considered a planet, at least as far as the International Astronomical Union was concerned. The decision was a long time coming, but no person deserves more credit/blame for forcing the astronomical community's hand than Caltech astronomer Michael Brown. He and his team discovered a number of objects in the outer Solar System -- Eris, Haumea, Sedna, and others...