The heart of an astronaut actually gets smaller when in outer space.
216
The population of the Earth has more than doubled since 1950.
151
Sound doesn't travel in space.
255
In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
It takes eight and a half minutes for light to get from the sun to earth.
159
If two pieces of metal touch in space, they become permanently stuck together.
808
Pluto is smaller than Russia.
9
Jupiter's moon Ganymede, is larger than the planet Mercury!
149