It 'snows' metal on Venus.
13
The population of the Earth has more than doubled since 1950.
151
Some asteroids have other asteroids orbiting them.
131
Approximately 115 tons of ocean salt spray enters the earth's atmosphere each second.
100
A 100-pound person on Earth would weigh 38 pounds on Mars.
102
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9