Uranus: the mould-breaker

(excerpted from my book, Sun, Moon and Stars)

The seventh planet dealt a serious blow to old ideas about the universe. From the beginning, Uranus lived up to its association with innovation and technology. When William Herschel found Uranus in 1781, he used an exciting new technology, the telescope.

Galileo had built an early telescope himself, with which he saw the moons of Jupiter in 1610, but by the 1700s the telescope was in use not only in astronomy but also in the shipping industry and the military.

The Politics of Uranus

800px-William_Herschel01Perhaps astrologers should also associate Uranus with toadyism – Herschel called his new planet Georgium Sidus, after George III, the reigning king and his patron. Most astronomers rejected this, for obvious reasons. Eventually Johann Bode‘s proposal of Uranus found favour with the majority of astronomers, since it was in keeping with the mythological names of the other planets.

John Flamsteed by Godfrey Kneller, 1702 (Wikimedia)
John Flamsteed by Godfrey Kneller, 1702 (Wikimedia)

Uranus had been found before, by John Flamsteed, who published the first star catalogue in 1690. The hitch was that he thought it was a star, which he called 34 Tauri (34th star in Taurus). You can just see Uranus if you know where to look and it’s having a bright period. It will look like a faint star. It is more visible through binoculars, but the best view comes from a telescope, which will reveal a pale aqua-blue planet.

The (Pale) Blue Planet

The colour is the result of methane in Uranus’ atmosphere, which absorbs red light. Like all the gas planets (Jupiter through Neptune) it has rings, although they are dark and faint. The rings were discovered in 1977 by two teams of scientists (one American, one Australian), who noticed changes in the light from the planet, which was caused by rings blocking the light.

William Herschel also recorded seeing the rings, although this is controversial, because unlike Saturn’s rings they are dark in colour and harder to see.

The Voyager 2 spacecraft confirmed the existence of rings, as well as discovering most of Uranus’ 27 moons. These are named for characters in plays by Shakespeare (especially “A Midsummer Night’s Dream”) and Alexander Pope.

sp_uranus-1440x900Uranus has a tilt of 98 degrees on its axis, so its poles are where the equator should be. (Earth’s tilt is about 23 degrees.) Astronomers haven’t decided which one is the north pole yet. To add to the oddness, it rotates in the opposite direction to the Earth. Only it and Venus rotate east to west.

It takes 84 years to get round the sun, and has 20-year seasons. Whichever pole faces the sun has a day that lasts all summer, because of Uranus’ odd rotation. As the planet orbits the sun, the other pole gets the sunlight for 42 years, as well as warmer weather.

Uranus in Myth

When Bode suggested Uranus as the name for the seventh planet, he was following the mythological sequence already begun by Jupiter and Saturn. Uranus was the original sky-god in Greek mythology (Ouranos, to give him his Grecian name, but the planets have traditionally had Latin names). He was the son and husband of the Earth, named Gaea, or Tellus if we were being consistent. But we’re not.

Gaea and Ouranos had many children – the 12 Titans, the Cyclopes and three beings with 100 hands and 50 heads each. Ouranos objected to the Cyclopes and 100-handers and sank them into Tartarus, deep in the bowels of the earth. Since Gaea was the earth, this caused her great pain. She incited Kronos to castrate his father by way of revenge.

When Kronos severed the link between earth and heaven, the Cyclopes and 100-handers escaped. Kronos re-imprisoned them, even though they were relatives. Later they would side against him in his conflict with his own son Zeus.

Ouranos just meant “heaven” or “sky” as Gaea meant “earth”. His myths, however, didn’t really connect to the astrological meanings of his planet, which really related to the shock of Uranus’ discovery. There is something neat about the oldest god giving his name to the then-youngest planet, all the same.

Astronomers honoured the first man to spot Uranus in its symbol: the H-shaped bit reflects one of the other names proposed for Uranus: Herschel. In astrology, Uranus rules the unexpected or unconventional, new technology and humanitarianism. This related to the time of its discovery, since the French and American revolutions were the most important events of the second half of the 1700s.

Not surprisingly, its metal is uranium, and its colour is electric blue. Uranus rules Aquarius, along with Jupiter. You can listen to Holst’s Uranus the Magician by clicking the link.





6 thoughts on “Uranus: the mould-breaker

  1. Voyager did not discover the rings. They were discovered in 1977, using the Kuiper Airborne Observatory. Interestingly William Herschel also reported a possible ring sighting in 1789.


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