41% of the moon is not visible from earth at any time.
103
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The Earth weighs around 6,600,000,000,000,000,000,000 tons (5,940 billion billion metric tons)!
221
More than 20 million meteoroids enter Earth's atmosphere every day.
139
Lightning strikes about 6,000 times per minute on this planet!
158
Only 55% of Americans know that the sun is a star.
986
Approximately 115 tons of ocean salt spray enters the earth's atmosphere each second.
100