The atmosphere of Uranus consists mostly of hydrogen (82.5%), helium (15.2%), and methane (2.3%).

The diameter of Uranus is 31,763 miles (51,118 km). Just for comparison, this about 4 times bigger than the diameter of the Earth.

Ariel's brightness increases dramatically when it is in opposition--that is, when the observer is directly between it and the Sun. This indicates that its surface is porous, casting reflectivity-decreasing shadows when illuminated at other angles.

Winds on Uranus can travel as fast as 560 miles per hour.