This is a formative assessment probe designed to elicit student ideas about why constellations that we can view in the night sky change with the seasons. It poses a situation of a class visit to the planetarium where the program is about the summer sky. A student asks the instructor to show the constellation Orion. The student must give an explanation for why the instructor cannot do that. This probe offers four possible ideas that the student might have used to explain why the instructor is unable to show Orion. After students make a choice, they then justify their choice with reasoning by explaining their thinking. The information and activity suggestions contained in the teacher notes assists in curriculum and lesson planning.