This year we have a few more options to choose from and I think we will end up at a Planetarium that I have been wanting to take my son to anyway! It is the perfect opportunity to explore your area or expand and make it a day trip!
Go to the Smithsonian Free Museum Admission site and find your state to see what museums near you are participating. You will have to log in or create an account (don't worry it's free!) Then print out your ticket for admission for two. Have fun on Saturday!