Brian Marsden, keeper of the records of the solar system

Obituary in the Economist:

Mr Marsden’s other somewhat controversial stand was on Pluto, calling on the IAU to downgrade its planetary status. It was not just that Pluto was small; it also had an orbit mathematically very similar to those of a bunch of other things discovered in the 1990s and 2000s. To Mr Marsden orbits, rather than size or history, were the key to the definition. (He also felt that the only reason anyone was fussed about the matter was that Pluto was the only “planet” to have been discovered by an American.)