AuroracastUKLearn
Uranus
Tipped over on its side, and just about visible with the naked eye if your sky is dark enough.
Seeing it from the UK
This is where it stops being easy. Uranus sits right on the edge of naked eye visibility, so from a properly dark sky, with no Moon, knowing exactly where to look, some people can just about pick it out. Most cannot. Ordinary binoculars show it easily once you know where it is, but as a star rather than a disc, and a small telescope only turns it into a tiny greenish dot. It is a planet you tick off rather than admire.
Uranus is the odd one. Every other planet spins roughly upright as it goes round the Sun. Uranus is tipped over by 98 degrees, so it rolls along its orbit on its side, almost certainly knocked there by something very large a long time ago.
That tilt gives it the strangest seasons in the solar system. For about twenty one years at a time one pole points more or less at the Sun while the other sits in complete darkness, and then it swaps. A single Uranian year lasts 84 of ours, so a winter there is longer than most human lives.
The picture is not a poor one. Uranus genuinely looks like that: an almost featureless pale blue green ball. The colour comes from methane in its atmosphere, which absorbs red light. Voyager 2 flew past in 1986 and it is still the only spacecraft ever to have been there.
The numbers
- Distance from the Sun
- About 1.8 billion miles, nineteen times further out than us
- A day there
- 17 hours 14 minutes
- A year there
- 84 Earth years
- Axis tilt
- 98 degrees, so it orbits lying on its side
- Moons
- 28 known, named after Shakespeare and Alexander Pope characters
- Visitors
- One, Voyager 2, in 1986
To find out whether it is up tonight, and when it gets properly dark where you are, see Sky Tonight.