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
On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
7
Jupiter is bigger than all the other planets combined.
254
Jupiter has radio storms so strong that they can be picked up and heard by an AM radio.
16
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
Pluto is smaller than Russia.
9