“Mars has been a mystery to humans for thousands of years. Even though much is known about it, there is still much more to learn. Mars is the fourth planet from the Sun, and the planet most like Earth in the solar system. It is named after the mythical god of war whom the Romans called Mars and the Greeks called Ares. Mars is also known as the Red Planet, because it looks reddish from Earth. Mars is a dusty, cold world. The average temperature is –64 degrees Fahrenheit. Rays of ultraviolet radiation beat down on the surface continuously. The atmosphere is nearly all carbon dioxide.”