Clyde W. Tombaugh, born on February 4, 1906 in Streator, Illinois. He attended school there and then moved to a farm in Kansas with his family.
His interest in all thing astronomical was nurtured by both his father and his uncle, who encouraged him as he taught himself about astronomy.
He graduated from high school in 1925, and around that time, there that a hail storm took out of all the family's crops, and killing his dream of going to college.
When he was 20, Clyde built his first telescope using hand-ground mirrors and parts of farm equipment to do so. He built two more in the next two years, grinding his own mirrors and lenses, and learning all he could about optics.
Going back in history a little bit, prior to 1781, everyone knew that there were six planets in the solar system, but in that year, William Herschel was the first person in recorded history to discover a new planet: Uranus. Herschel was unable to postulate why it refused to conform to the laws of Newtonian physics, and there was much discussion, with the end result being that by 1830, most people thought that there must be another plant behind Uranus. In 1846, Neptune was discovered by astronomers in Berlin. Neptune served to explain some of the erratic behavior of Uranus, but not all. Naturally, the speculation was that there was still another planet behind Neptune.
The driving motivation of Percival Lowell, the wealthy Harvard-educated Bostonian who, in 1894, built the observatory, was finding the ninth planet, a dim and distant body was he called Planet X. Lowell had developed a method by which he believed Planet X could be detected, but it was tedious and involved spending many hours in the cold, unheated observatory dome, snapping photographs of the night sky, night after night, and comparing the pictures without aid of automation. None of the "real" astronomers wanted that job.
Meanwhile, with the aid of his telescopes, Clyde drew Jupiter and Mars, sending them to Flagstaff, Arizona's Lowell Observatory, where he made an impression on the astronomers there who had been looking for an amateur astronomer who could operate there new photographic telescope. Timing being everything, they invited him to work at the observatory on a trial basis, which he did for the next 14 years.
On February 18, 1930, American astronomer Clyde Tombaugh discovered the dwarf planet Pluto. Pluto, located some 3 billion miles from the sun, takes more than 250 years to orbit the sun a single time. Charon, Pluto's moon, is almost have the size of Pluto itself and orbits Pluto every 6.4 days.
During his tenure at the Lowell Observatory, he discovered hundreds of asteroids as well as hundreds of new variable stars, the comet known as C/1931 AN, and numerous other heavenly bodies.
He also designed new instruments, including the super camera IGOR (Intercept Ground Optical Recorder), which is in use even now at White Sands Missile Range in Las Cruces, New Mexico, where he worked after he left Lowell Observatory in order to serve in World War II. IGOR stood exactly as Clyde had designed it for more than three decades before any improvements upon it were even thought of.
From 1955 until he retired in 1973, Clyde taught at New Mexico State University in Las Cruces.
He died in his home in 1997, just before he would have turned 91.
In 2006, after years of debate, the International Astronomic Union voted to change the definition of the word "planet," and Pluto was declared no longer a planet. The public reaction was against this decision, and several states took legislative action denouncing it, including California, New Mexico, and Illinois, Clyde's home state, which passed a resolution asserting that the planet had been "unfairly downgraded.
And if there is any doubt as to the importance of this decision, the wort "pluto" became a verb. The American Dialect Society chose "plutoed" as its Word of the Year in 2006, and defined it as "to demote or devalue someone or something."
Nasa: Solar System Exploreation
Dwarf Planet Pluto
Pictures of Pluto