41% of the moon is not visible from earth at any time.
103
The sun puts out more power in 1 second than mankind has ever used within human existence.
14
The light hitting the earth right now is 30 thousand years old.
163
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
Sound doesn't travel in space.
255
Summer on Uranus lasts for 21 years.
358
The population of the Earth has more than doubled since 1950.
151
An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9