Mars and Earth: With a radius of 3,390 kilometers, Mars is about half the size of Earth. If Earth were the size of a nickel, Mars would be about as big as a raspberry.

The 'God of War': Mars was named by the ancient Romans for their god of war because its reddish color was reminiscent of blood. Other civilizations also named the planet for this attribute, the Egyptians calling it "Her Desher," meaning "the red one."

The Red Planet: Mars is actually many colors. At the surface, we see colors such as brown, gold, and tan, however, Mars looks reddish due to oxidization or rusting of iron in the rocks, regolith (Martian “soil”), and dust of the red planet.

Phobos and Deimos: Mars has two small moons, Phobos and Deimos, which are potato-shaped because they have too little mass for gravity to make them spherical. Mars' moons get their names from the horses that pulled the chariot of Ares, the Greek god of war.

Life on Mars: While scientists don't expect to find living things currently thriving on Mars, they're looking for signs of life that existed long ago, when the planet was warmer and covered with water.