A comet's tail always points away from the sun.
2
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
13
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
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277
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
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
If you were to cry in space, the tears would form a bubble in your eye until it's so big it moves to another spot on your face.
10