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 are approximately 3,500 astronomers in the U.S. - but over 15,000 astrologers.
124
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
Summer on Uranus lasts for 21 years.
358
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
The heart of an astronaut actually gets smaller when in outer space.
216