Drawing of William Herschel – Uranus is in the background

You can see several planets without a telescope. People have been seeing Mercury, Venus, Mars, Jupiter and Saturn for thousands of years. Even though Uranus was the first planet discovered by telescope, sometimes it can be seen without one.

For 18th century astronomers, Saturn was the outer edge of the Solar System.
This sketch by James O'Donoghue shows the distances of the planets from the Sun in AU (astronomical units). An AU is the distance from the Earth to the Sun, about 150 million km (93 million miles). You can see that Saturn is almost 10 times farther from the Sun than Earth is.

An amazing discovery
William Herschel was a German musician and amateur astronomer living in England. In April 1781 he had been looking for double stars when he came across a slightly fuzzy object. When he looked for it a few nights later, it had moved. Stars aren't fuzzy and they don't appear to move, so he thought he had found a comet.

Other astronomers looked for Herschel's comet. Only a few of them didn't think it was a comet. The Astronomer Royal at Greenwich Observatory was one of those who thought Herschel might have discovered a new planet.

From the time the first telescopes looked to the Moon until the first discovery of a planet was about 170 years.
But Herschel wasn't the first person to see Uranus. Nearly a century earlier, the first Astronomer Royal, John Flamsteed, saw it a number of times. He catalogued it as a star. During that century a few of the other astronomers that saw it also also thought it was a star.

Herschel had the advantage of the excellent telescope he had himself built. But even he needed to be convinced about what he had discovered. Astronomer Anders Johan Lexell spent several months observing "the comet" and calculating its orbit. It was clearly a planet, the first to be discovered.

Uranus is far away, so it's faint and small. It also moves very slowly, so may not seem to change position. But probably a reason for not spotting a new planet was that people weren't expecting to see one.

A new view of the Solar System
You can see from the O'Donoghue sketch that Uranus is twice as far from the Sun as Saturn is. Herschel's discovery doubled the size of the known Solar System.

Naming the new planet
Herschel named the planet Georgium Sidus [George's Star] after George III, the king of England. People in other countries had other names for the planet, but outside England no one called it George.

German astronomer Johann Bode proposed the name Uranus which would continue the classical mythology. The Roman gods Mercury, Venus and Mars were among the many children of Jupiter. Jupiter himself was the king of the gods. His father was Saturn who had ruled until Jupiter overthrew him. But we can't feel sorry for Saturn because he had fought and exiled his own father Uranus.

Uranus was adopted by most astronomers as a name for the new planet. Finally in 1850, even England officially accepted Uranus and erased Georgium Sidus.

Some people have seen Uranus without a telescope.
Uranus can be seen without a telescope or binoculars at some times. But to see it you'd need to know where it is, and have both a dark sky and good eyesight. It's so hard to see that Uranus is not listed as a naked eye planet.

Uranus has been visited by a space probe.
Voyager 2 visited in 1986. Another probe is planned for launch in 2031 or 2032.