1. To compare the surfaces of Mercury, Venus, and Mars, do Interactive Exercise 7-3 on the Web. You can print out your results, if requested. 2. As seen from Earth, the brightness of Venus changes as...

1. To compare the surfaces of Mercury, Venus, and Mars, do Interactive Exercise 7-3 on the Web. You can print out your results, if requested.

2. As seen from Earth, the brightness of Venus changes as it moves along its orbit. Describe the main factors that determine Venus’s variations in brightness as seen from Earth. (Hint: See the discussion of Venus in Chapter 2.)