Astronomer Percival Lowell believed that he was the first person to observe canals on Venus, but because of a faulty adjustment of the eyepiece on his telescope, he was in fact looking at the blood vessels in his own eye.
4
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
A comet's tail always points away from the sun.
2
The population of the Earth has more than doubled since 1950.
151
The Earth gets 100 tons heavier every day due to falling space dust.
673
Earth is the only planet in our solar system that's not named after a god or goddess.
17
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
There are two golf balls sitting on the moon.
721