Why Is Mars Called The "Red Planet?"

The entire surface of Mars is covered by a thin layer of iron oxide.

Mars is the fourth planet from the Sun and is the second smallest planet in the Solar System, larger only than Mercury. Nicknamed the "Red Planet," Mars was named after the Roman god of war. The planet is approximately 143 million miles from the Sun, which it orbits every 687 Earth days. Solar days on Mars are longer than on Earth, with a time of 24 hours, 39 minutes, and 35.244 seconds, which means that one year on Mars is equivalent to 1.8809 Earth years. Mars can be seen from Earth with the naked eye, and is easily identifiable due to its red coloring, resulting in its nickname as the "Red Planet."

Origin of the “Red Planet” Nickname

Mars is commonly referred to as the "Red Planet" because it appears red or orange in the sky. In fact, its reddish color can be seen clearly by the naked eye. In ancient Greek, the planet's name is linked to its red appearance and was named after the god of war. The Ancient Greeks thought that the color red signified the blood-thirsty god Mars, who rode on a chariot pulled by Deimos and Phobos, the twin gods that symbolized terror and fear, respectively, in Greek mythology. As a result of this mythology, the two moons of Mars were named Deimos and Phobos. Additionally, the ancient Egyptians referred to Mars as Har decher, which means "red one." Modern technology and spacecraft have enabled scientists to confirm that the surface and skies of Mars appear red in certain sunlit conditions. 

Cause of Mars' Reddish Color

In addition to red and orange, Mars can also appear butterscotch in color. The planet's reddish appearance is caused by the presence of iron oxide, or rust, on its surface. In fact, the entire surface of Mars is covered by a thin layer of iron oxide, as iron is one of the most abundant elements in the crust of Mars. When iron is exposed to water and oxygen, which are also present on Mars, a reaction occurs, creating a film of iron oxide that is red-orange in color. The iron oxide on Mars may have formed a long time ago when the planet had significant amounts of water. The rusty material was likely distributed across the planet by dusty clouds. In fact, Mars experiences dust storms that can occur at any time and obscure the entire surface of the planet. These dusty clouds cause everything on Mars to be covered by rust.

Other Common Colors on Mars

Mars is not entirely red, but actually features a variety of different colors including tan, brown, golden, and greenish. The wide range of colors that can be observed on the surface of the planet depends on the mineral present. In addition to iron, the surface of Mars contains other elements such as magnesium, calcium, aluminum, and potassium. Some regions may also appear bright orange, while others appear brown or even black. A few inches below the red surface is actually brown in color. Unlike on Earth, where the sunset is orange, the sunset on Mars is actually blue.


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