The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Astronauts cannot burp in space.
232
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The typical spec of dust that you see floating in the air is half way in size between the Earth and a subatomic particle.
131
The light hitting the earth right now is 30 thousand years old.
163
The population of the Earth has more than doubled since 1950.
151