Category: 7. Other Worlds: An Introduction to the Solar System

Review Questions 1: Venus rotates backward and Uranus and Pluto spin about an axis tipped nearly on its side. Based on what you learned about the motion of small bodies in the solar system and the surfaces of the planets, what might be the cause of these strange rotations? 2: What is the difference between a differentiated…

For Further Exploration Articles Davidson, K. “Carl Sagan’s Coming of Age.” Astronomy. (November 1999): 40. About the noted popularizer of science and how he developed his interest in astronomy. Garget, J. “Mysterious Microworlds.” Astronomy. (July 2005): 32. A quick tour of a number of the moons in the solar system. Hartmann, W. “The Great Solar System Revision.” Astronomy. (August 1998):…

Learning Objectives By the end of this section, you will be able to: Much of astronomy is motivated by a desire to understand the origin of things: to find at least partial answers to age-old questions of where the universe, the Sun, Earth, and we ourselves came from. Each planet and moon is a fascinating…

Learning Objectives By the end of this section, you will be able to: How do we know the age of the surfaces we see on planets and moons? If a world has a surface (as opposed to being mostly gas and liquid), astronomers have developed some techniques for estimating how long ago that surface solidified.…

Learning Objectives By the end of this section, you will be able to: The fact that there are two distinct kinds of planets—the rocky terrestrial planets and the gas-rich jovian planets—leads us to believe that they formed under different conditions. Certainly their compositions are dominated by different elements. Let us look at each type in…

Learning Objectives By the end of this section, you will be able to: The solar system1 consists of the Sun and many smaller objects: the planets, their moons and rings, and such “debris” as asteroids, comets, and dust. Decades of observation and spacecraft exploration have revealed that most of these objects formed together with the Sun…

Surrounding the Sun is a complex system of worlds with a wide range of conditions: eight major planets, many dwarf planets, hundreds of moons, and countless smaller objects. Thanks largely to visits by spacecraft, we can now envision the members of the solar system as other worlds like our own, each with its own chemical…