Postcard from the Edge: Evidence Points to Big, Undiscovered Planet
By David Rosen & Eric Francis Coppolino It’s not every day that a new planet announces its existence, but that depends on what you mean by planet. Moons, asteroids, centaurs, comets and dwarf planets are discovered relentlessly. Nearly a million are known and catalogued, all objects orbiting our Sun. The great majority have been spotted … Read more