|
|
|
|
Ancient astronomers didn’t know there were any planets farther away than Saturn. But in 1781 an English astronomer called William Herschel found one. It was named Uranus. It lies twice as far away as Saturn, and takes 84 Earth-years to circle around the Sun. Like all the planets, Uranus spins on its axis. Most planets spin nearly in the upright position as they travel in their orbits. But Uranus is tipped right over on its side as it travels. That’s why we call it the ‘topsy-turvy’ planet. Uranus is made up of gas and liquid gas, like Jupiter and Saturn, but is smaller. We can’t spot it with the naked eye, but we can see it through a telescope. It is pale bluish-green in colour. Like Jupiter and Saturn too, Uranus has a system of rings around it, although they are much too faint to be seen from Earth, even through a telescope. We can, however, see the five largest of the 15 or more moons that circle around the planet. The most interesting one is Miranda. The Voyager space probes have shown that it looks like no other body on the Solar System. Astronomers think that long ago it was smashed into pieces when it collided with a big asteroid. Then the pieces came together again to create the peculiar landscape we see now. |
|
|
|
