In multiple civilizations, the planet Mars was named for its red color. The ancient Romans named Mars after their god of war because of its red, blood-like hue. The ancient Greeks named the planet Ares after their war god. The Chinese called it "the fire star," and the Egyptians called the planet "Her Desher," which means "the red one."
The reason for Mars' red, rusty hue is the loose rock and dust covering its surface, which is made of minerals that are rich in iron.
The landscape on Mars consists of many low-lying, flat plains. At its lowest point, the northern plains are some of the smoothest and flattest in the solar system.
Mars is home to the highest mountain and largest volcanoes in the solar system, including one that is approximately 370 miles in diameter and roughly 17 miles high, called Olympus Mons. Mars also has a system of valleys, which can be 6 miles deep in some locations, that runs approximately 2,500 miles long, making the Valles Marineris the longest and deepest valley in the solar system, according to Space.com.
Mars is about 30 percent less dense than Earth. Scientists believe that Mars has a solid core, based on it having a smaller magnetic field than Earth, according to About.com.