Mars is known for its red color, although when you see actual photos of Mars taken on the planet, many colors are present.
So what makes Mars the Red Planet? And why doesn’t it always look red in close-up?
Well, Mars appears red (or red-orange) is because its surface contains a large amount of rust or iron oxide. The iron oxide dust in its atmosphere causes the planet to appear very rusty from space. However, when you are in Mars, you will see that there are other colors because there are other minerals existing on the planet. Some iron oxides come in different colors too, and not just green.
So where does Mars gets all its rust? Many scientists believe that the abundance of iron oxide on Mars was pushed up from the volcanoes that used to erupt. Iron oxides or rust may have been formed due to solar radiation causing atmospheric water vapor to react with the iron. Iron oxides may have also come from meteorites that are iron-based.