This American astrologer discovered the planet Pluto. In 1929, Tombaugh was hired as a junior astronomer to join in the search for a planet X, beyond Neptune. He made wrold news on March 13th 1930, when his discovery of the ninth planet, Pluto, was confirmed. Over the next 13 years, he discovered six star clusters, 2 comets, hundreds of asteroids, several dozen galaxies, and one super cluster. He was also instrumental in working out the vortex nature of Jupiters great Redspot. The rotation period of Mercury on its axis, and in the developement of a new photographic technique, that could observe small Earth's satellites.

Christiaan Huygens

He was a dutch physicist and astronomer, who was born in 1620 and died in 1695. He found new methods for grinding and polishing lenses.

He invented the telescope for space research.

Huygens was a prominent Dutch mathematician, and natural philosopher..astronomer, physicist, probabalist and horologist. Huygens was a leading natural philosopher in his time. His work included early telescopic studies of the rings of saturn, and the discovery of its moon-Titan. He was also responsible for the invention of the pendulum and many other inventions in time keeping. He eventually produced machines and optics. He was also responsible for working on the first games of chance (gambling).