Clyde Tombaugh

On this date in 1906, Clyde Tombaugh, who discovered Pluto, was born in Streator, Illinois. As an amateur astronomer in the 1920s he made drawings of Jupiter and Mars which earned him a job at the Lowell Observatory, where he worked from 1929 to 1945. In his first year at Lowell, he undertook a search for a predicted planet outside the orbit of Neptune, discovering the body that was named Pluto in 1930. No other trans-Neptunian objects were found until 1992; now the region in which Pluto orbits is known as the Kuiper belt, the discovery of which could be credited to Tombaugh as he spotted the first object in the region. Tombaugh was also credited with discovering 15 asteroids, a periodic comet, as well as hundreds of variable stars, star clusters, galaxy clusters, and a galaxy supercluster. He died before Pluto was reclassified as a dwarf planet, but a portion of his ashes were stored aboard the New Horizons spacecraft which flew past Pluto late last year.

Date in History: 4 February 1906