The population of the Earth has more than doubled since 1950.
151
Astronauts get taller when they are in space.
224
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
The Earth gets heavier each day by tons, as meteoric dust settles on it.
118
A comet's tail always points away from the sun.
2
