Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Astronauts cannot burp in space.
232
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
If two pieces of metal touch in space, they become permanently stuck together.
808
Lightning strikes about 6,000 times per minute on this planet!
158
Only 55% of Americans know that the sun is a star.
986
41% of the moon is not visible from earth at any time.
103
If you were to cry in space, the tears would form a bubble in your eye until it's so big it moves to another spot on your face.
10