Mars

If Earth were the size of a nickel, Mars would be about as big as a raspberry. It's diameter is 4212 miles (6779 km).  The reason Mars looks reddish is due to oxidization – or rusting – of iron in the rocks, regolith (Martian “soil”), and dust of Mars. This dust gets kicked up into the atmosphere and from a distance makes the planet appear mostly red. Mars has a thin atmosphere made up mostly of carbon dioxide, nitrogen, and argon gases. Mars' sparse atmosphere doesn't offer much protection from impacts by such objects as meteorites, asteroids, and comets. It takes Mars 687 Earth days or 669.6 sols (short for solar days) to revolve around the sun. Because Mars's atmosphere is so thin, heat from the Sun easily escapes this planet. So temperatures on Mars can be as high as 70°F (20°C) or as low as about -225°F (-153°C).  Mars has two small moons, Phobos and Deimos, that may be captured asteroids. They're potato-shaped because they have too little mass for gravity to make them spherical. Mars was named by the ancient Romans for their god of war because its reddish color was reminiscent of blood. Mars's Greek counterpart was the Greek god of war, Ares.