Summer on Uranus lasts for 21 years.
358
It takes eight and a half minutes for light to get from the sun to earth.
159
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
There are approximately 3,500 astronomers in the U.S. - but over 15,000 astrologers.
124
The Earth gets 100 tons heavier every day due to falling space dust.
673
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121