Pluto and the Dwarf Planets
Pluto was discovered by Clyde Tombaugh on February 18, 1930 at Lowell Observatory in Flagstaff, AZ. The observatory’s founder, Percival Lowell, had predicted a planet with a mass seven times that of Earth beyond Neptune’s orbit. However, at an apparent magnitude of 15, Pluto was 2.5 magnitudes too dim to be the expected planet. Pluto … [Read more…]