*Answer to Challenge Question (p. 31 of Max Goes to the Moon):
When we see a new moon, people on the Moon would see a full Earth. To understand why, look at the picture on p. 31. We see new moon when the Moon is directly between the Sun and the Earth. Thus, people on the Moon at that time would be looking at the sunlit face of the Earth, which means a full Earth. If you want to understand this better, try the Phases of the Moon tutorial.
