Uranus----A lying revolving planet

The rotation of Uranus is very unique and its rotation and revolution axles are inclined to be vertical with the degree of 98。It revolves the Sun in lying position. Some scientists thought that the retrograde probably is caused by the bombardment made by any body of the size of the Earth. Even the orbit of Uranus is inclining and it implies the origin of satellites has something to do with the severe bombardment received by Uranus.

There are rings on the equator of Uranus and they can be divided into 11 thin rings with the width of tens of kilometers each, which is thinner and darker than those of Saturn. As a result, we are not able to observe through naked eyes and we need to use HST observations. HST observations is taking advantage of the moment when Uranus and its rings pass through a fixed star, it will shield the light of that star and it will enable us to measure the position and width of rings. Uranus has 15 moons and five of them are large ones with the radius of 20-80 kilometers. There is no clear answer to how these moons are formed.