How Do You Name A Planet?

Discover a planet and you get to name it. But when Lowell Observatory announced its new planet, it had no name ready. Hundreds of people wrote offering all sorts of possibilities, from Atlas to Zymal . Zymal , one letter writer explained, was “the last word in the dictionary” for “the last word in planets.” Lowell’s widow, Constance, who had delayed the Planet X work for over a decade, came up with a number of suggestions, culminating in one she sent in a note to Slipher: “Are you willing to have the planet named Constance?” He never replied.

Minerva , Cronus , and Pluto emerged as the three top choices. But Minerva was already the name of an asteroid, and Cronus had been used by a planet hunter for another still-undiscovered world. So that left Pluto, god of the underworld, a god who, like the planet, lay in perpetual dark (Pluto is so far away that little sunlight reaches it). The first person to suggest the name was Venetia Burney, an elevenyear-old from Oxford, England. The first two letters of Pluto , it was pointed out, are the initials of the astronomer who inspired the search that led to the discovery. So the name honors Percival Lowell.