(Background) This beautiful image of the whole Earth was taken by a weather satellite hovering over the equator. One can clearly see Africa and the Middle East (with desert areas prominent in both), as well as Europe (at top).
(Inset A) A band of cirrus clouds cuts across Egypt, the Nile River, and the Red Sea ( upper left) in this (southward) view taken by a crewed spaceship in Earth orbit.
(Inset B) The Red Sea, separating Egypt (right) from Saudi Arabia (left) and the Sinai Peninsula is a new ocean being formed as the African continent begins to drift away from Asia Minor.
(Inset C) Here, the southern tip of the Sinai Peninsula is centered, with the Red Sea at the top, the Gulf of Aqaba at lower left, and the Gulf of Suez at right.
(Inset D) An even closer view of desolate sand dunes in Arabia. The long dunes parallel the prevailing wind direction and can be up to 150 meters high and 600 kilometers long without a break.
Studying this chapter will enable you to:
Summarize the overall physical properties of planet Earth.
Explain how Earth's atmosphere helps to heat us as well as protect us.
Outline our current model of Earth's interior structure and describe some of the experimental techniques used to establish this model.
Discuss the nature and origin of Earth's magnetosphere.
Summarize the evidence for the phenomenon of "continental drift" and discuss the physical processes that drive it.
Describe how both the Moon and the Sun influence Earth's oceans.
Earth is the best-studied terrestrial planet. From the matter of our world sprang life, intelligence, culture, and all the technology we now use to explore the cosmos. We ourselves are made of "earthstuff" as much as are rocks, trees, and air. Now, as humanity begins to explore the solar system, we can draw on our knowledge of Earth to aid our understanding of the other planets. By cataloging Earth's properties and attempting to explain them, we set the stage for our comparative study of the solar system. Every piece of information we can glean about the structure and history of our own world plays a potentially vital role in helping us understand the planetary system in which we live. If we are to appreciate the universe, we must first come to know our own planet. Our study of astronomy begins at home.
