I Don't Know What To Do With My Life?

I don't know what I want to do for a profession when I grow up. I have a 4.0, and plan to keep that up for the rest of high school. I'm a freshman now and am very interested in astronomy, I love it, but if I were to go to college for it, what would I do as an astronomer? So my back up career is to be a veterinarian or doctor. So should i do my passion or what will make me money? I need to know so I know what classes to take.