John Herschel discovered Uranus in 1781 while searching for double stars. There had been recent developments in Newton’s mathematics that would allow astronomers to calculate the orbits of celestial bodies and he wanted to learn more about the physical nature of stars. When he first saw Uranus through his seven-foot reflecting telescope, he thought it was a comet. Very few astronomers believed there was a possibility of more planets, other than the five they knew of, the moon, and the sun. It wasn’t until a Russian astronomer calculated the orbit of the “comet”, following a slow moving path, that it was determined that it was a planet.

Since Herschel’s discovery, scientists have discovered more than two hundred extrasolar planets outside