after gus moves to LA, his parents still expect the occasional visit. which means that since rosie was little, there have been times when an uncle-gus-and-rosie day fell on a gus-has-to-go-see-his-parents day. the first time this happened shawn literally just said "so take her with you", and obviously bill and winnie adore her. but that's also the origin of gus starting to take rosie to the SB space center, which was always one of gus's favorite places, and rosie gets into space too. that combined with asking denny's mom (karen) about her job (mars rovers at JPL) has rosie getting into astronomy early on, but it's also the memories made with her uncle gus (she thinks the griffith observatory is cool and all, but the santa barbara space center will always be her favorite)
