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
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
It 'snows' metal on Venus.
13
Summer on Uranus lasts for 21 years.
358
Earth is the only planet in our solar system that's not named after a god or goddess.
17
Saturn's moon, Mimas, not only looks like the Death Star, it also has a Pac Man heat signature.
15