Uranus, the first Planet to be discovered

Wednesday, 08 September 2010 14:29

Written by Editor

In ancient times people knew that there were 5 strange objects in the sky that wandered throughout the stars so they called them Planetès from the Greek word meaning wanderers. We call them planets.

Mercury, Venus, Mars, Jupiter and Saturn were well known to ancient astronomers but in 1781 Sir William Herschel, a German born but English astronomer and music composer discovered a brand new planet, Uranus. The name Uranus, which has been the butt of a thousand schoolboys’ gags for many years, was not his first choice.

Originally Herschel was going to name the Planet ‘George’s Star’ after King George III. But this name was not very popular outside of Britain, especially with the French and Americans who were at war with us at the time!

It’s surprising that Uranus wasn’t discovered before 1781 as it can sometimes come just within the range of being seen with the naked eye and there is evidence to suggest that it had actually been seen before Herschel discovered it, but it was considered to be just another star as it moves so slowly against the background stars. And if you have a pair of binoculars or a small telescope then this month you will be able to see Uranus for yourself.

For the whole of September Uranus will be less than 1° from the planet Jupiter so it will appear in the same field of view as Jupiter as seen through your binoculars. Go outside after about 10pm and locate Jupiter, which is the very bright ‘star’ you can see rising in the east, now using your binoculars, focus on Jupiter and just slightly above it you will see a tiny blue coloured disc; this is Uranus.

Uranus, which is pronounced with the ‘A’ as in apple not ‘A’ as in day, is a strange world. The Earth has a tilt of about 23° from being straight up whereas Uranus is titled over by more than 97° which means that during its 84 year orbit around the Sun then it is in fact rolling around on its side with one pole receiving 42 years of sunlight and then 42 years of darkness.

It is about 3 billion km from the Sun which means that the light and heat it receives from the Sun is about 1/400th of the light that we receive making it a very cold dark place to be. It has more than 27 moons orbiting about it; the five largest, Miranda, Ariel, Umbriel, Titania and Oberon are all named after characters from Shakespeare’s plays.
So stop tittering about its name and go outside and show Uranus to all your friends!

The ISS.

Our friends at NASA are sending the International Space Station back again this weekend. Look to the North West on Sunday September 12th at 9:35pm and you will see it passing at 17,000mph across the sky. Don’t forget to get the kids to give the astronauts a big wave because the captain says he’s going to lean out of the window and wave back at you!