Suppose there is an infinite number of moons in a row that all reflect the light waves on to the next one, each receiving it's causal power from the previous moon. If every single member of the series doesn't have the power to produce light in and of itself, it's hard to see how we're going to explain the existence of the property of light waves, where each of member never has the power of producing light by themselves, but only derivatively. So I don't think this is going to help, and we have to posit something which possesses that property essentially. 

Maybe a Humean would say that there's no such thing as global explanations, and that there are only local facts that contingently explain other facts to an extent. However, that seems to beg the question, and I think  the explanation above would do better than the Humean's, as we're able to explain more than them. That said, I'm not too sold on the notion of there being physical examples of such a series, I take it that arguing the existence of such a series is a totally metaphysical affair.