Kent State Planetarium is a small university-run astronomy venue that opens to the public for scheduled shows. It is a good fit for travelers already spending time in Kent, especially if you want an inexpensive indoor stop with more substance than another shop or cafe.
The draw is the programmed sky show rather than a walk-in museum experience, so check the calendar before planning around it. When sessions are running, it adds a thoughtful science note to a town otherwise best known for its campus history and compact downtown.