On February 18, 1930, Pluto was discovered by Clyde Tombaugh of the Lowell Observatory in Flagstaff, Arizona. Only three major bodies in our solar system have official discovery dates, as nearer objects can be seen with the naked eye and have been observed for centuries. Before Pluto, the latest major discovery within our solar system was of Neptune back in 1846, so the discovery of Pluto is fairly recent in comparison.
You probably know that Pluto is no longer considered a planet—it was classified as a dwarf planet in 2006—but what else do you know about Pluto? Take the quiz in honor of the 90th anniversary of Pluto’s discovery!