A comet's tail always points away from the sun.
2
Sound doesn't travel in space.
255
A lightning bolt generates temperatures five times hotter than those found at the sun's surface!
127
The Earth gets 100 tons heavier every day due to falling space dust.
673
The heart of an astronaut actually gets smaller when in outer space.
216
Summer on Uranus lasts for 21 years.
358
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 density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219