Category: 9. Cratered Worlds

For Further Exploration Articles The Moon Bakich, Michael. “Asia’s New Assault on the Moon.” Astronomy (August 2009): 50. The Japanese Selene and Chinese Chang’e 1 missions. Beatty, J. “Slams the Moon.” Sky & Telescope (February 2010): 28. The impact of the LCROSS mission on the Moon and what we learned from it. Bell, T. “Warning: Dust Ahead.” Astronomy (March 2006): 46.…

Learning Objectives By the end of this section, you will be able to: 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 in this chapter, it also shares with the Moon the likelihood of a violent birth. Mercury’s Orbit…

Learning Objectives By the end of this section, you will be able to: It is characteristic of modern science to ask how things originated. Understanding the origin of the Moon has proven to be challenging for planetary scientists, however. Part of the difficulty is simply that we know so much about the Moon (quite the opposite of…

Learning Objectives By the end of this section, you will be able to: The Moon provides an important benchmark for understanding the history of our planetary system. Most solid worlds show the effects of impacts, often extending back to the era when a great deal of debris from our system’s formation process was still present. On Earth,…

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 surface features—those that can be seen with the unaided eye and that make up the feature…

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 from a planet just the way a rocket does, and the lower the gravity, the…

The Moon is the only other world human beings have ever visited. What is it like to stand on the surface of our natural satellite? And what can we learn from going there and bringing home pieces of a different world? We begin our discussion of the planets as cratered worlds with two relatively simple…