Mercury
LEARNING OBJECTIVES By the end of this section, you will be able to: Mercury’s Orbit The planet Mercury is similar to the Moon in many ways. Like the Moon, it has no atmosphere, and its surface is heavily cratered. As described later…
The Origin of the Moon
LEARNING OBJECTIVES By the end of this section, you will be able to: Ideas for the Origin of the Moon It is characteristic of modern science to ask how things originated. Understanding the origin of the Moon has proven to be challenging…
Impact Craters
LEARNING OBJECTIVES By the end of this section, you will be able to: Volcanic Versus Impact Origin of Craters The Moon provides an important benchmark for understanding the history of our planetary system. Most solid worlds show the effects of impacts, often…
The Lunar Surface
LEARNING OBJECTIVES By the end of this section, you will be able to: General Appearance If you look at the Moon through a telescope, you can see that it is covered by impact craters of all sizes. The most conspicuous of the Moon’s…
General Properties of the Moon
LEARNING OBJECTIVES By the end of this section, you will be able to: The Moon has only one-eightieth the mass of Earth and about one-sixth Earth’s surface gravity—too low to retain an atmosphere (Figure 9.2). Moving molecules of a gas can escape…
Cosmic Influences on the Evolution of Earth
LEARNING OBJECTIVES By the end of this section, you will be able to: In discussing Earth’s geology earlier in this chapter, we dealt only with the effects of internal forces, expressed through the processes of plate tectonics and volcanism. On…
Life, Chemical Evolution, and Climate Change
LEARNING OBJECTIVES By the end of this section, you will be able to: As far as we know, Earth seems to be the only planet in the solar system with life. The origin and development of life are an important part of…
Earth Atmosphere
LEARNING OBJECTIVES By the end of this section, you will be able to: We live at the bottom of the ocean of air that envelops our planet. The atmosphere, weighing down upon Earth’s surface under the force of gravity, exerts a…
Earth Crust
LEARNING OBJECTIVES By the end of this section, you will be able to: Let us now examine our planet’s outer layers in more detail. Earth’s crust is a dynamic place. Volcanic eruptions, erosion, and large-scale movements of the continents rework the…
The Global Perspective
LEARNING OBJECTIVES By the end of this section, you will be able to: Earth is a medium-size planet with a diameter of approximately 12,760 kilometers (Figure 8.2). As one of the inner or terrestrial planets, it is composed primarily of heavy…