Why is Uranus blue, is it made of water

A. No, in fact, Uranus doesn't have a liquid or solid surface that anything could land on. Its atmosphere is made of gas, mainly hydrogen, helium and methane.

The methane absorbs the sun's red light and reflects back blue light, giving it a distinctive blue colour.

Q. If it's a gas giant, does it have rings

A. Yes, like the gaseous giants Jupiter and Saturn, Uranus has a system of rings, 11 in total which first spotted in 1977.

Q. What took the scientists so long to discover them

A. The rings of Uranus are very different from those of Jupiter and Saturn. They're so dark that even a space ship close to the planet would have trouble seeing them. The only way to 'see' them is when they block out the light of the starts behind and beyond them

Q. How long is a day on Uranus

A. Things are a little unusual on Uranus because, unlike the other planets in our solar system, Uranus has a unique orientation: it's effectively tipped on its side. This means that half the time either one of its poles is facing the sun. This means that it's 'night' on Uranus for half of it's 'year', that's 42 of our Earth years.

Q. Nice to have such long summers though

A. Not really, because Uranus is so far from the sun, it's the seventh planet, it never gets warm, even during its 42-year summer temperatures don't rise above -200C.

Q. Why does it have this unique orientation

A. It's possibly the result of with a collision with a large, planet-sized object, earlier in the planets history.

Q. The name is guaranteed to make people snigger, but what does Uranus really mean

A. When Wilhelm Herschel originally discovered the planet in 1781 he named it 'the Georgium Sidus'(the Georgian Planet). It's latter name, Uranus, is the name of the Greek god of the heavens, continuing the tradition of naming planets after Classical gods.

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by Lisa Cardy