Why is Mars Red?

For thousands of years, we have been looking up to the sky and seeing the beautiful red planet that we call Mars. Ancient Egyptians saw it best in the night sky and called it ‘the red one’. The Greeks and Romans thought it was powerful and named it after their god of war: Mars. Some people were afraid of it and others thought Mars was a powerful guardian.

Planet MarsSince we started sending missions to Mars we had the ability to see it close up and we have found out that Mars is a lot more complicated than we thought. The Mars rovers, Spirit and Opportunity, took actual samples of the Mars soil and they found that it was made of rust. The dusty rust layer was all over the planet, giving it the reddish color. And it isn’t just one color, but quite a few different types of reddish-brown.

Mars pictured in natural color

The rust layer is very thin and Mars has such large storms that they sometimes cover the entire planet. Underneath this layer is a volcanic rock that is very similar to earth. Mars has some of the largest dust storms in the galaxy, whipping red dust into the light atmosphere around the planet. This is why the pictures of Mars appear to have a red sky. So why doesn’t the rust blow away? Well it seems that some of it does blow out and away from the planet, but scientists are discovering that Mars might just be making more of the rust.

Rust on earth is made from iron and water, but there isn’t any water on the surface of Mars. Earth has a lot of iron, but most of it sunk to the middle of the planet when earth was formed. Mars, on the other hand is called a ‘dead’ planet, and it is covered in rust. Scientists think that at one time, Mars could have been a lot like earth, but when it lost most of its atmosphere, the ancient volcanos blew out all of the iron in its center and spread it all over the planet.

silica-rich dust on Mars

In November, 2013, NASA sent the MAVEN mission to Mars, hoping to get more information on just what Mars is made of. They are finding that Mars may not have water on the surface, but it may contain water deep below. In the meantime, scientists have been doing experiments to see if rust can be made without water. A couple of them have figured out how rust can be made without having any water at all.

We all know that the earth has polar caps filled with frozen water. Well it seems that Mars has polar caps as well. With MAVEN’s help, we should be able to see if the polar caps are made of ice water.

So Mars is red because it has a layer of rusty dust covering the whole surface, and, if the scientists are right, it is blowing some of it out into space and then making more. As it makes more, the dust storms blow it across the planet and it keeps its red color. Mars has polar caps and we hope to find out soon if they are made of water.