Mars had an oxygen-rich atmosphere around 4 billion years ago
13
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
A comet's tail always points away from the sun.
2
The center of the galaxy tastes like raspberries and smells like rum, according to astronomers.
4
If NASA sent birds into space they would soon die; they need gravity to swallow.
146
Summer on Uranus lasts for 21 years.
358