Scientists know of 750,000 or so asteroids and comets—and all of them are part of this fine solar system. That is, all of them but one. And as new research shows, it’s weird as hell. Today, scientists are reporting their analysis of ‘Oumuamua, an interstellar object spotted last month. The oddly-shaped, fast-moving rock immediately surprised astronomers with its chemical makeup and other properties, which implied there should be far more interstellar objects floating around than previously thought.