It takes a thick skin to withstand the hardships that life has to offer. This collection of images shows a variety of animals, each with a slightly different type of protective covering.

This video segment adapted from NOVA explains why ice sheets move. To find out how fast they move, scientists carve a tunnel through a glacier.

What would happen if a portion of the Antarctic Ice Sheet were to melt? This video segment adapted from NOVA uses animations to show the effect of a 6-meter sea-level rise on coastal cities across the world.

What happens when the ground under your feet is ice and it's moving? This video segment adapted from NOVA features some of the dangers faced by scientists conducting research in Antarctica.

This video segment adapted from NOVA uses microwave images to reveal how sea ice doubles the size of Antarctica each winter. Rare footage shows how sea ice crushed the famous ship Endurance in 1914.

This video segment adapted from Building Big illustrates the strength of the arch in bridge design and construction.

This video segment from Wild Europe: "Wild Arctic" explores the struggle for survival in one of Earth's most extreme environments.

This video segment adapted from NOVA features a variety of scientific perspectives on the age old question, "Are we alone in the universe?" Animations make vivid the improbability that we could intercept a radio wave signaling extra terrestrial intelligence.

This video segment explores the benefits and pitfalls of cloning as a means of reproduction. From Evolution: "Why Sex?"

Explore some of the wonders of modern engineering in this video from the Sciencenter in Ithaca, New York. Hear a diverse selection of engineers explain how things work.

In this video segment produced for Teachers' Domain, Andres Berrio, an associate scientist at Biogen Idec, discusses what he has done to succeed in the biotechnology field.

In this feature, adapted from Interactive NOVA: "Earth," students explore the relationship between oxygen concentration and the well-being of various organisms by simulating a change in oxygen levels and observing what happens.

In this interactive activity from ChemThink, take a closer look at atomic structure, properties, and behaviors.

This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

The engineering design process involves many steps. Not only must an engineer be able to devise a solution to a problem, he or she must also be ready to test and evaluate that solution to reach the best result. To successfully complete the design process, an engineer must be able to identify design flaws and learn from his or her mistakes. In this video segment adapted from ZOOM, learn about the design process as cast members create automatic door openers that enable them to open their bedroom doors while lying on their beds. For grades 3-8.

The impact of natural disasters is made vivid in this video segment adapted from NOVA. A small town in Iceland, prepared for recurrent avalanches, is devastated when one takes a new and damaging path.

In this video from DragonflyTV, Jai and Jonathan track, graph, and analyze the motion of basketball shots as they investigate what factors influence the accuracy of their game.

This audio excerpt captures the beginning of Bayard Rustin's 1967 "Freedom Budget" speech, describing the social and economic impact of racism over time.

This video segment explores the world of the beaver, including the biology of the species and, more importantly, its ability to transform an ecosystem for its own benefit.

This video segment describes how the Australopithecus afarensis skeleton known as Lucy could have been fossilized. Footage courtesy of NOVA: "In Search of Human Origins."