41% of the moon is not visible from earth at any time.
103
It takes eight and a half minutes for light to get from the sun to earth.
159
The light hitting the earth right now is 30 thousand years old.
163
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
In the last 7 years, humanity has discovered 43 potentially habitable planets.
14
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
A 100-pound person on Earth would weigh 38 pounds on Mars.
102