Pluto is smaller than Russia.
9
Venus is the only planet that rotates clockwise.
310
41% of the moon is not visible from earth at any time.
103
The typical spec of dust that you see floating in the air is half way in size between the Earth and a subatomic particle.
131
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
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