Eighty-five years ago this week, astronomers at the Lowell Observatory in Arizona sent a telegram to Harvard registering their discovery of another planet in our solar system. The news made the front page in New York, Chicago, and elsewhere, and was morning conversation in a London household where 11-year-old Venetia Burney lived. “My grandfather read out at breakfast the great news and said he wondered what it would be called,” she remembers in a 2006 interview with NASA. “And for some reason, I after a short pause, said, ‘Why not call it Pluto?’” We look back on that moment in this week’s One Last Thing.