Mars had an oxygen-rich atmosphere around 4 billion years ago
13
If two pieces of metal touch in space, they become permanently stuck together.
808
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
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
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 moon, Mimas, not only looks like the Death Star, it also has a Pac Man heat signature.
15