- Saturn's moon, Titan, has its own atmosphere, but you wouldn't want to live there, as it's poisonous to breathe.
- past 800°F. Space probes that landed on the planet were destroyed by the temperatures in just hours!
- Earthlings can spot Mercury pass across the face of the Sun 13 times per century. The next "transit" will be in May 2016.
- Most of Uranus's 27 moons are named for Shakespearean characters.
- An icy and stormy planet, Neptune's winds are nine times stronger than those on Earth.
- The Haughton crater in the Canadian High Arctic is thought to have similar terrain as Mars and is the site for much research on the red planet.
Follow the break for more facts on the wild planet worlds of space.
- The deepest spot on Earth is called the Challenger Deep, which is located in the Mariana Trench of North Pacific Ocean and measures to a depth of 35,827 feet.
- The International Astronomical Union's official definition of a planet is: "A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces, so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit." Sorry, Pluto.
- We're not so special. Since 1991, astronomers have found over 450 planets outside of our solar system that orbit stars.