On Aug. 24, 2006, the International Astronomical Union declared that Pluto was no longer a full-fledged planet, demoting it to the status of a “dwarf planet.” Pluto, which is in fact smaller than Earth’s moon, was quickly heralded as the ninth planet in the solar system when it was spotted Feb. 18, 1930, by Tombaugh, a young amateur astronomer stationed at Lowell Observatory. “Planet Pluto, 1930-2006″