Jupiter's moon Ganymede, is larger than the planet Mercury!
149
If you went out into space, you would explode before you suffocated because there's no air pressure.
149
The Earth weighs around 6,600,000,000,000,000,000,000 tons (5,940 billion billion metric tons)!
221
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 Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
Sound doesn't travel in space.
255
Tidal forces between the Earth and Moon are slowing the Earth down and pushing the Moon further away.
46