Everyone always calls Mars the "Red Planet" because the Martian surface is covered with a reddish-brown
sand. You can do this experiment to find out what Martian sand is made of, and why it is red.
- Pour a layer of sand into the cake pan.
- With the gloves on, use scissors to cut the steel wool into small chunks. Be careful to keep all the pieces in the pan -- they can be sharp!
- Mix the steel wool and sand together with your hands, again, keep those gloves on.
- Fill the pan with enough water to just cover the mixture.
- Leave the pan in a level, safe place.
- Each day, check the pan, and add water to it so that it always stays wet.
- Watch what happens to the color of the mixture over the course of several days.
Martian sand contains iron and oxygen, the same ingredients you added to your sand mixture. When iron comes
into contact with water and oxygen, it rusts and turns a reddish-brown-just like your bike will rust if left
in the rain. Scientists think there was once enough water on Mars that the whole planet rusted and turned
red-a color we can see all the way from Earth.