The population of the Earth has more than doubled since 1950.
151
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
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
Sound doesn't travel in space.
255
41% of the moon is not visible from earth at any time.
103
Only 55% of Americans know that the sun is a star.
986
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121