Why is the moon white?

We asked cosmologist Sarafina Nance to answer this colourful question...

Sarafina - That's a good question. There are several different aspects to this answer. One is that the Moon doesn't have life on it. The Earth has oceans and has different landmasses. The other thing is the Moon is composed of various elements, like oxygen and silicon that contribute to the grey colour of the Moon that we see. Then you have this volcanic activity where a lot of the rocks that are under the surface have actually been expelled from the inside of the Moon during volcanic eruptions, and then end up on the surface of the Moon. But ultimately I think the big thing is that when we look at the Moon from the Earth, we are seeing it as particles in the atmosphere scatter certain types of wavelengths of light. Blue is scattered very easily and red isn't and depending on where the Moon is in the atmosphere, that's closer to the horizon versus higher up in the atmosphere, the moon actually changes colour.

John - What's in the middle of the Moon?

Sally - Cheese, John. Don't you know?

Sarafina - I think Sally has the best answer. There's some volcanic activity on the Moon, but it has a lot of impact craters from various planetary bodies and other sorts of bodies that have rammed into it, but I actually don't know what the substructure is as you penetrate the surface of the Moon.