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
Saturn's moon, Mimas, not only looks like the Death Star, it also has a Pac Man heat signature.
15
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
A 100-pound person on Earth would weigh 38 pounds on Mars.
102
More than 20 million meteoroids enter Earth's atmosphere every day.
139
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
Mars had an oxygen-rich atmosphere around 4 billion years ago
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