Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Pluto is smaller than Russia.
9
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
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Jupiter has radio storms so strong that they can be picked up and heard by an AM radio.
16
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
41% of the moon is not visible from earth at any time.
103