(Background) In this close-up image of Jupiter, taken by the Voyager 2 spacecraft, the moon Io is clearly visible. One of the most peculiar moons in the solar system, and certainly the most active, Io's multihued surface is caused by various chemical compounds deposited by currently active volcanos.
(Inset A) Photo of Io taken by Voyager 1 with a remarkable resolution of 7 km. The red color results largely from sulfur compounds, the white areas covered probably with sulfur dioxide frost.
(Inset B) At top left, a plume from an erupting volcano, known as Prometheus, is clearly seen at the limb of Io against the blackness of space.
(Inset C) Many lava flows can be seen on Io, like this one stretching for several hundred kilometers across the moon's surface.
Studying this chapter will enable you to:
Specify the ways in which Jupiter differs from the terrestrial planets in its physical and orbital properties.
Discuss the processes responsible for the appearance of Jupiter's atmosphere.
Describe Jupiter's internal structure and composition and explain how these are inferred from external measurements.
Summarize the characteristics of Jupiter's magnetosphere.
Discuss the orbital properties of the Galilean moons of Jupiter and describe the appearance and physical properties of each.
Explain how tidal forces can produce enormous internal stresses in a jovian moon, and discuss the results of those stresses.
Beyond the orbit of Mars, the solar system is very different from our own backyard. The outer solar system presents us with a totally unfamiliar environment—huge gas balls, peculiar moons, complex ring systems, and a wide variety of physical and chemical phenomena, many of which are still only poorly understood. Although the jovian planets—Jupiter, Saturn, Uranus, and Neptune—differ from one another in many ways, we will find that they have much in common, too. As with the terrestrial planets, we will learn from their differences as well as from their similarities. Our study of these alien places begins with the jovian planet closest to Earth—Jupiter, the largest planet in the solar system and a model for the other jovian worlds.
