41% of the moon is not visible from earth at any time.
103
There are approximately 3,500 astronomers in the U.S. - but over 15,000 astrologers.
124
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
All of the Earth's continents are wider at the north than in the south - and nobody knows why.
194
The sun puts out more power in 1 second than mankind has ever used within human existence.
14
On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
7