Infini.to is Turin's astronomy museum and planetarium, set on the hillside at Pino Torinese near the historic astronomical observatory. Its exhibits cover space, light, gravity, and the scale of the universe in a hands-on way, which makes it a useful change of pace from Turin's palaces and churches.
The trip is most rewarding when paired with the hill views back over the city and toward the Alps. Check language options and show times before you go; the planetarium programme is the main event, and it is worth timing your visit around a projection rather than treating the museum as a quick drop-in.