In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
The earth travels through space at 660,000 miles per hour.
189
If you went out into space, you would explode before you suffocated because there's no air pressure.
149
There are 5 to 10 times more stars in the known Universe than there are grains of sand on all the world's beaches, but a single grain of sand has more atoms than there are stars in the known Universe.
20
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
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 heart of an astronaut actually gets smaller when in outer space.
216