Mars had an oxygen-rich atmosphere around 4 billion years ago
13
There are 5 to 10 times more stars in the known Universe than there are grains of sand on all the world's beaches, but a single grain of sand has more atoms than there are stars in the known Universe.
20
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
If NASA sent birds into space they would soon die; they need gravity to swallow.
146
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277
Tidal forces between the Earth and Moon are slowing the Earth down and pushing the Moon further away.
46