Hello, I'm currently a philosophy major and I'm going to start my sophomore year this fall, but I've considered changing my major to astronomy. The problem with this is that I've always wanted to graduate in just 4 years, and the only way this could happen is if I filled up the next two summers with many summer classes. My university though offers many research opportunities during the summer, and it would probably be foolish to turn down these opportunities. There are research opportunities I can do during the academic year, but the opportunities during the summer seem like they'll be better for graduate school resumes. At the same time though, I would not be able to take any summer classes if I take part in any of them. If if don't take any summer classes, I'll have at least two semesters in my undergraduate years that I'll be taking only 12-14 credit hours due to my lack of prerequisite classes needed to take the required physics courses for my school's astronomy degree plan. Would it be better for graduate school if I spend 5 years as an undergraduate student or to take summer classes and do all my researching during the school year? Thanks in advance.