Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
Only 55% of Americans know that the sun is a star.
986
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
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
All of the Earth's continents are wider at the north than in the south - and nobody knows why.
194
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277