I've heard that the moon is one of the most reduced environments known, what is reduced and why is this?

Question

Reducing environment would be one which electrons are gained? (reduced = gain electrons, lower charge right?), and there would be lots of ionizing radiation on the surface of the moon due to no atmosphere and lots of sun light. But why would the ionizing radiation reduce the surface? What is being reduced? and why couldn't the radiation oxidize the surface instead?

Answer 1

There's no oxygen on the moon, so it can't oxidise. I'm not a chemist, but I think that on the earth, the radiation would cause the rock to oxidise, but on the moon there is no atmosphere, so the rock reduces.