Diameter: 4,200 miles across
Location: 4th planet from Sun
Distance from Sun: About 142 million miles
Number of Moons: 2
Average Surface Temperature: Summer 32° Fahrenheit; Winter -150° Fahrenheit
Orbital Period: 687 Earth days
Characteristics: The atmosphere is made up of three gases: carbon dioxide, nitrogen, and argon.
Identity in Mythology: Mars, the Roman god of war

(Image: Grolier Interactive)