A comet's tail always points away from the sun.
2
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
According to a study by the National Science Foundation, only half of Americans believe in evolution, and one in 4 don't know that the Earth orbits the Sun.
14