I would definitely encourage you to study planetary science or aerospace engineering. I did not go back to school to get my Ph.D. until my daughters were in school. I am very glad I decided to pursue an advanced degree. It has helped my career as a scientist tremendously. In twenty years you will be able to contribute a great deal.
Astrobiology is a growing field right now with the possibility of looking for life on other planets.
We chatted with you last year. The flybys of Venus and Earth were both very successful. We looked for lightening on Venus but did not see it. We also got pictures of the moon. The pictures and data are on JPL's home page.