Describes the characteristics of various types of comets and their relationship to Earth with specific emphasis on Halley's comet, its appearances throughout history, and the preparations for its return in early 1986. Includes a glossary of terms.
Discusses Voyager's space exploration mission, how the spacecraft conducts experiments using scientific instruments, and discoveries revealed about Jupiter, Saturn, and Uranus.
A description of an expedition to explore a glacier in Alaska introduces facts about glaciers, including their origin, types, and effects on the earth.
Explores what causes earthquakes, where the tremendous power of a quake comes from, why they occur without warning, and whether it is possible to predict earthquakes.
