41% of the moon is not visible from earth at any time.
103
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
The volume of the Earth's moon is the same as the volume of the Pacific Ocean.
178
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
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
The Earth gets 100 tons heavier every day due to falling space dust.
673
The Earth gets heavier each day by tons, as meteoric dust settles on it.
118