The clearly written text is combined with simple, colorful pictures to make the concepts of day and night and the rotation of the earth in relation to the sun very understandable for both young children and their parents. : ) Included is a very simple hands-on "experiment" requiring only your child and a desk lamp. Some information about the moon is also covered. Like other books in this series, this book is a great solution for satisfying some of those "why" questions that young children constantly ask.