Explains what comets are, how they are formed, and how their unusual orbits bring them into earth's view at predictable intervals, with a special focus on Halley's comet.
Introduces the solar system and its nine planets. Includes directions for making two models, one showing relative sizes of the planets and the other their relative distances from the sun.
Explains various changes in humanity's beliefs about the shape of the earth, from the flat earth theories of the ancients to the round earth theories which were proven true by the voyages of Columbus and Magellan.
