The heart of an astronaut actually gets smaller when in outer space.
216
The earth travels through space at 660,000 miles per hour.
189
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
The population of the Earth has more than doubled since 1950.
151
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
An international team of astronomers has spotted the farthest known gravitational lens and, as Albert Einstein predicted, it is a galaxy that deflects and intensifies the light of a much further object.
9
A comet's tail always points away from the sun.
2