The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
41% of the moon is not visible from earth at any time.
103
It 'snows' metal on Venus.
13
Jupiter is bigger than all the other planets combined.
254
An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9
Pluto is smaller than Russia.
9