Summer on Uranus lasts for 21 years.
358
Sound doesn't travel in space.
255
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
Astronauts cannot burp in space.
232
Astronauts get taller when they are in space.
224
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
Some asteroids have other asteroids orbiting them.
131