Hi there!

Yes you can absolutely become anything you want to be. Just right direction and passion is all that needs to drive you towards your goal. PhD is essential for you to get a deeper and indepth understanding of your area of research in astrophysics. All the major leading astrophysicsts are Doctorate degree holders. However PhD is the highest educational level of qualification. It needs years of continuous hard work and patience.

Wish you all the best for your future endeavors.

Good luck.