Discovery of Uranus 

On March 13, 1781, William Hershel discovered Uranus, the first of the planets to be discovered in modern times.

Prior to Hershel’s discovery, all of the known planets were identified thousands of year prior. In fact, other stargazers had seen the planet as early as 128 BC, but believed it was a star.

Herschel, the first to discover a planet using a telescope, initially believed what he saw was a comet, and not a planet. He first observed Uranus on March 13, 1781, at his home in Somerset, England. Using a telescope of his own design, he then conducted a series of observations of the stars to track it.

When he presented his findings to the Royal Society, Herschel concluded that it was a comet, while still comparing it to a planet. When he informed another astronomer of his discovery, he received the confused reply, “I don’t know what to call it. It is as likely to be a regular planet moving in an orbit nearly circular to the sun as a Comet moving in a very eccentric ellipsis. I have not yet seen any coma or tail to it.”

Though Herschel was still convinced he’d found a comet, others believed it was a planet. Anders John Lexell studied its orbit and found it to be almost entirely circular, which convinced him it was a planet and not a comet. About two years after his discovery, Herschel admitted that it must be a planet, and it was generally accepted as such. For his role in the planet’s discovery, Hershel received an annual stipend and moved to Windsor so the Royal Family could use his telescopes.

However, naming the new planet would be the matter of debate for nearly 70 years. As its discoverer, Herschel was given the honor of naming the new planet. He wanted to name it Georgium Sidus (George’s Star), or the “Georgian Planet” after King George III. He believed all the other planets had been named after gods because they were those cultures’ heroes. So he reasoned that, “if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third’.”

However, most people outside of Britain didn’t like Herschel’s idea. One astronomer suggested it be named for Herschel, while another suggested Neptune. German astronomer Johann Bode proposed Uranus, the Latin name for the Greek god of the sky Ouranos. Bode believed that the name should be based in mythology as all the others were, so it wouldn’t stand out. It also seemed fitting since Saturn was the father of Jupiter, so the new planet should be named after the father of Saturn.

The name Uranus caught on and received widespread support. The newly discovered element uranium was named to show support for Bode’s idea. By 1850, Uranus was officially adopted as the name for the seventh planet.

Click here for more on Uranus from the NASA website.

Click here for lots more space stamps.

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