Physics GRE Discussion Forums

I've been working through my undergraduate time mostly concentrating on physics, especially astrophysics. Recently, however, I have gotten a growing interest in much of the earth sciences. After looking over a few schools that were on my grad school list, I noticed some of them have planetary science programs linked to their astronomy programs, but most do not. I do not think I want to apply directly to study earth sciences (I would like to stay in physics) but linked grad school programs would very much appeal to me. I was wondering if anyone knew of any good schools where studying both topics in graduate school would be possible or anyone was in a similar situation and had some general advice on how to proceed.

Thanks.