Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
All of the Earth's continents are wider at the north than in the south - and nobody knows why.
194
A lightning bolt generates temperatures five times hotter than those found at the sun's surface!
127
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The center of the galaxy tastes like raspberries and smells like rum, according to astronomers.
4
There are approximately 3,500 astronomers in the U.S. - but over 15,000 astrologers.
124