Understanding the power of magnetism on Earth isn't always easy, and students and teachers alike will be glad to find out about this handy guide to the subject. Created by experts at NASA, this 15-page teacher's guide was designed in partnership with other educators at Berkeley as well as several other participating institutions. The guide contains problems which examine Earth's changing magnetic field in time and space, and how these changes can impact navigation on Earth's surface. In terms of specific activities, the guide includes exercises on navigating the earth with a compass, the declining magnetic field, and the reversal of magnetic polarity. Each of these activities is explained in detail, and they all include relevant illustrations, graphs, questions, and an answer key.