Uranus

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Let's get one thing out of the way up front. Astronomers pronounce it Yoora-nus, not Yoo-raynus. They say that this follows the original Greek pronunciation of the god of the sky, Ouranos, but really it is to stop people sniggering. So we will stick to Uranus here, and let you lot do all the jokes.

The story of its discovery is a really good one. There was an 18th century German musician, William Herschel,  who made his home in England, in Bath in fact. He became interested in astronomy, but found that telescopes at that time were expensive and not very good anyway, so he made his own. He set about finding double stars, which meant looking at thousands of stars to see if they were one point of light or two. Then he came across one which showed a tiny disc rather than a point of light. It turned out to be the planet we now call Uranus.

Initially he wanted to call the star Georgium Sidus, or George's Star, because the king at the time was King George III, you know, the one who went mad, who was fellow Hanoverian. But this didn't go down too well with foreign astronomers. Let's face it, Planet George is only slightly less silly than Your-anus. It was another German, Johann Bode, who suggested Uranus to be in keeping with the classical names of the other planets known at the time. But it was not until 1850, nearly 70 years after Herschel discovered the planet, that the name Uranus was finally agreed by everyone.

Actually, even if it hadn't been for his discovery of Uranus we would still remember Herschel today, because he made several other important discoveries, including infrared radiation. The house in Slough where he built his giant telescope was pulled down in the 1960s, but he is buried in Slough and you can find a Herschel Street and a Herschel Park in Slough.

Herschel's home-made telescope was better than any at the Royal Observatory at the time, and after he became the King's Astronomer he had a profitable sideline in making telescopes. His sister Caroline made a name for herself discovering comets, and his son John became one of the most famous scientists of the 19th century. It was John Herschel who invented the modern method of photography, a word which he himself coined, along with the terms 'negative' and 'positive' referring to photographic film.

In fact, John Herschel made the first photographic negative ever of the great telescope, just before it was dismantled in 1839 because the wooden framework was getting rotten. In its day the instrument, 40 feet long and with a mirror 48 inches (120 cm) across, was the largest in the world, and became a tourist attraction. Those were the days, when Slough was the centre of the Universe!

Beyond Saturn the Solar System gets quite empty. Even on our scale model, it will take you several minutes to get to the next planet out, Neptune. In the real Solar System, there are many comets out at this distance, so we've added a typical comet on the way. 

Photo: Uranus with its rings and 10 satellites; image taken by Voyager 2 in 1986.
Credit: Erich Karkoschka/University of Arizona