Some asteroids have other asteroids orbiting them.
131
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
More than 20 million meteoroids enter Earth's atmosphere every day.
139
Only 55% of Americans know that the sun is a star.
986
The heart of an astronaut actually gets smaller when in outer space.
216
A 100-pound person on Earth would weigh 38 pounds on Mars.
102
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82