Once or twice in a generation's rhythm of looking up, the sky offers something that rewards the effort without demanding expertise. This week over Metro Vancouver, the International Space Station — a football-field-sized laboratory carrying human beings at 420 kilometres above Earth — will arc visibly across the night sky, threading through the Big and Little Dippers on Thursday evening. It is a reminder, available to the naked eye, that the boundary between the ordinary and the extraordinary is sometimes only a matter of knowing when to step outside.