Mars had an oxygen-rich atmosphere around 4 billion years ago
13
A lightning bolt generates temperatures five times hotter than those found at the sun's surface!
127
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
41% of the moon is not visible from earth at any time.
103
If two pieces of metal touch in space, they become permanently stuck together.
808
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
