Pluto is smaller than Russia.
9
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Astronauts get taller when they are in space.
224
Summer on Uranus lasts for 21 years.
358
Sound doesn't travel in space.
255
It would take more than 150 years to drive a car to the sun.
569
Venus is the only planet that rotates clockwise.
310
Tidal forces between the Earth and Moon are slowing the Earth down and pushing the Moon further away.
46