Jupiter is bigger than all the other planets combined.
254
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 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
Some asteroids have other asteroids orbiting them.
131
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 two golf balls sitting on the moon.
721
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
13