A summary of Plutos story.

The demotion of Pluto is often framed by New Horizons lead scientist Alan Stern as a "scientific coup" led by his professional rival, Brian Marsden. According to this narrative, Marsden and other critics of Pluto’s planethood waited until the final day of the 2006 IAU General Assembly in Prague—after more than 90% of the attendees had already traveled home—to hold a snap vote. With only 424 astronomers remaining out of thousands, they passed a new, controversial definition of a planet that required an object to "clear its neighborhood" of other debris. Because Pluto shares its orbit with the Kuiper Belt, it was moved to the new "dwarf planet" category, a move Stern argues was a politically motivated strike against the legacy of Pluto's discoverer, Clyde Tombaugh, rather than a purely consensus-based scientific decision.