Asteroids The solar system includes many objects that are much smaller than the planets and their larger moons. The rocky ones are generally called asteroids. Ceres is the largest asteroid; about 15 are larger than 250 kilometers and about 100,000…
LEARNING OBJECTIVES By the end of this section, you will be able to: The comets we notice when they come near Earth (especially the ones coming for the first time) are probably the most primitive objects we can study, preserved…
LEARNING OBJECTIVES By the end of this section, you will be able to: Comets differ from asteroids primarily in their icy composition, a difference that causes them to brighten dramatically as they approach the Sun, forming a temporary atmosphere. In…
LEARNING OBJECTIVES By the end of this section, you will be able to: Not all asteroids are in the main asteroid belt. In this section, we consider some special groups of asteroids with orbits that approach or cross the orbit of Earth.…
LEARNING OBJECTIVES By the end of this section, you will be able to: The asteroids are mostly found in the broad space between Mars and Jupiter, a region of the solar system called the asteroid belt. Asteroids are too small to be seen…
Figure 13.1 Hale-Bopp. Comet Hale-Bopp was one of the most attractive and easily visible comets of the twentieth century. It is shown here as it appeared in the sky in March 1997. You can see the comet’s long blue ion tail and the shorter…
Ring and Moon Systems Introduced The four jovian planets are accompanied by impressive systems of moons and rings. Over 200 moons have been discovered in the outer solar system. Of the four ring systems, Saturn’s is the largest and is…
LEARNING OBJECTIVES By the end of this section, you will be able to: In addition to their moons, all four of the giant planets have rings, with each ring system consisting of billions of small particles or “moonlets” orbiting close to their…
LEARNING OBJECTIVES By the end of this section, you will be able to: Pluto is not a moon, but we discuss it here because its size and composition are similar to many moons in the outer solar system. Our understanding…
LEARNING OBJECTIVES By the end of this section, you will be able to: We shift our attention now to small worlds in the more distant parts of the solar system. Saturn’s large moon Titan turns out to be a weird cousin…