In 1969, around his birthday on July 20, the author had a conversation with his grandmother about the landing of two men on the moon. She doubted that it happened--and that it ever could happen. And she had good reasons. First, when we see it, the moon is always above the Earth. Anyone getting up to it could hardly stay on it for long: a person would fall off. Second, in any case, the moon was too small to hold one man, let alone two men and a vehicle. Furthermore, the moon changes shape. At one time, it is a full disk and, at another, a mere sliver. For a time, it disappears altogether.