Chapter 12, Problem 32EAP

Choose the best answer to each of the following. Explain your reasoning with one or more complete sentences.

1. The asteroid belt lies between the orbits of (a) Earth and Mars, (b) Mars and Jupiter, (c) Jupiter and Saturn.
2. Jupiter nudges the asteroids through the influence of (a) tidal forces, Cb) orbital resonances, (c) magnetic fields.
3. Can an asteroid be pure metal? (a) No; all asteroids contain rock, Cb) Yes; it must have formed where only metal could condense in the solar nebula, (c) Yes; it must be from the core of a shattered asteroid.
4. Did a large terrestrial planet ever form in the region of the asteroid belt? (a) No, because there was never enough mass
there, Cb) No, because Jupiter prevented one from accreting. (c) Yes, but it was shattered by a giant impact.

5. What does Pluto most resemble? (a) a terrestrial planet Cb) a Jovian planet (c) a comet
6. How big an object causes a typical "shooting star”? (a) a grain of sand or a small pebble [b] a boulder (c) an object the size of a car
7. Which have the most elliptical and tilted orbits? (a) asteroids (b) Kuiper belt comets [c) Oort cloud comets
8. Which are thought to have formed farthest from the Sun? (a) asteroids Cb) Kuiper belt comets (c) Oort cloud comets
9. About how often does a 1-kilometer object strike Earth? (a) every year (b) every million years lc) every billion years
10. What would happen if a 1-kilometer object struck Earth? (a) It would break up in the atmosphere without causing widespread damage, (b) Il would cause widespread devastation and climate change, (c) It would cause a mass extinction.