Summer on Uranus lasts for 21 years.
358
It 'snows' metal on Venus.
13
If NASA sent birds into space they would soon die; they need gravity to swallow.
146
There are more nerve cells in the human brain than there are stars in the Milky Way.
349
A comet's tail always points away from the sun.
2
An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9