Why is the Air Dirty?

by Isaac Asimov

Published 1 September 1997
A simple discussion of the causes and effects of air pollution and some ways to help prevent it.

What is an Eclipse?

by Isaac Asimov

Published 1 September 1997
A step-by-step description of how an eclipse occurs and the differences between a lunar and a solar eclipse.

Briefly describes how toilets are used to get rid of waste and how sewage is treated.

Why Does the Moon Change Shape?

by Isaac Asimov

Published 12 December 1991
Explains why the moon changes from crescent to full moon every twenty-nine and one-half days.

What is a Shooting Star?

by Isaac Asimov

Published 1 December 1991
Explains the nature of meteors or "shooting stars" and how they are different from real stars.

Why are Animals Endangered?

by Isaac Asimov

Published 1 August 1992
Discusses why certain animals have become endangered and what can be done to help them from becoming extinct.

Describes how the seasons affect people and other living things.

Why are Whales Vanishing?

by Isaac Asimov

Published 1 September 1997
Discusses how modern whale hunting methods have caused many species of whales to become endangered and what can be done to help protect the whales.