Ages 10-14 mark a period in which children develop a strong sense of whether science is 'for them,' a time that typically coincides with the start of middle school in the United States and their first exposure to more rigorous science classes and testing. Experiences with science in and out of school can shape children's motivation to choose science careers or participate in voluntary science classes later on, for better or worse. We explore the hypothesis that children who engage in more informal educational science experiences at the start of this period are more likely than their peers to obtain and maintain interest, curiosity, and mastery goals in science (together forming a construct called fascination). We measured 983 children's fascination with science at the beginning and middle of sixth grade. We found that the children who participated in informal science during this time were more likely to maintain or have greater fascination than at the start. These findings held while also controlling for many potentially confounding covariates and are robust across subgroups by gender and race/ethnicity. Further, the effects are largest for those children whose family generally supports their learning.