All of the Earth's continents are wider at the north than in the south - and nobody knows why.
194
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
A comet's tail always points away from the sun.
2
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
Today's top fuel dragsters take off with more force than the space shuttle.
120
A 100-pound person on Earth would weigh 38 pounds on Mars.
102
If you were to cry in space, the tears would form a bubble in your eye until it's so big it moves to another spot on your face.
10