A comet's tail always points away from the sun.
2
41% of the moon is not visible from earth at any time.
103
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
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
Lightning strikes about 6,000 times per minute on this planet!
158
More than 20 million meteoroids enter Earth's atmosphere every day.
139
Astronomer Percival Lowell believed that he was the first person to observe canals on Venus, but because of a faulty adjustment of the eyepiece on his telescope, he was in fact looking at the blood vessels in his own eye.
4
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147