On this day in 1781, William Herschel discovered Uranus.

7th Rock From the Sun. The German-born astronomer found the seventh planet from the sun. Uranus is also the third largest planet in terms of diameter.

Some Firsts.

• Herschel's discovery of a new planet was the first to be made in modern times.
• It was also the first to be made using a telescope. The telescope allowed Herschel to determine that Uranus was a planet instead of a star, as earlier astronomers believed.
  

I Think I'll Call It Georgium Sidus. Herschel named the planet Georgium Sidus, or the Georgian Planet, in honor of King George III of England. German astronomer Johann Bode later suggested naming the planet Uranus, since the other planets had been named after characters from classical mythology.

Who Was Uranus? The ancient Greek deity of the Heavens, and a predecessor of the Olympian gods.

What's It Like On Uranus?

• Gassy. The planet Uranus is a gas giant, like Jupiter and Saturn.
• Plenty of Hydrogen. It is made up of hydrogen, helium, and methane.
• Long Years. Uranus orbits the sun once every 84 earth-years.
• A Different Perspective. It's the only planet to spin perpendicular to its solar orbital plane.
  

Vacation Destination? Uranus has only been visited once, in terms of Earth missions. On January 24, 1986, the unmanned US spacecraft Voyager 2 came within 5.7 million miles of Uranus. The mission discovered 10 more moons, bringing Uranus' total to 15. It also could detect a system of faint rings.