The heart of an astronaut actually gets smaller when in outer space.
216
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
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
It 'snows' metal on Venus.
13
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
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 earth rotates more slowly on its axis in March than in September.
145
Pluto is smaller than Russia.
9