The familiar adage "seeing is believing" implies that children will recall a particular phenomenon if they had the experience of seeing it with their own eyes. If this were true, then most children would believe that one could see the Moon in both daytime and at night. However, when children are asked, "Can you see the Moon in the daytime?" many will say "no," even though they have actually seen the Moon many times in the morning or afternoon sky. The formative assessment probe, "Objects in the Sky," shows how persistent the belief is among elementary-age children that the Moon can only be seen in the nighttime. Understanding where the Moon is located at different times of the day and its changing appearance as viewed from Earth are important goals for learning. To achieve an understanding of these important learning goals, elementary students should have the opportunity to observe the position and phases of the Moon in both the daytime and nighttime sky. Before students engage in monthly observations to discover the pattern of Moon phases, consider using a probe such as "Objects in the Sky" to find out whether students recognize that the Moon can be seen in the daytime. (Contains 1 figure and 1 online resource.)