Summer on Uranus lasts for 21 years.
358
The typical spec of dust that you see floating in the air is half way in size between the Earth and a subatomic particle.
131
Venus is the only planet that rotates clockwise.
310
Astronomer Percival Lowell believed that he was the first person to observe canals on Venus, but because of a faulty adjustment of the eyepiece on his telescope, he was in fact looking at the blood vessels in his own eye.
4
It 'snows' metal on Venus.
13
The earth rotates more slowly on its axis in March than in September.
145
On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
7