Chapter 21, Problem 3LTL

Look at Figure 21-11. Which molecule(s) can escape from Earth’s gravity? From Mars? From Venus?

Figure 21-11 Loss of atmospheric gases. Dots represent the escape velocity and temperature of various Solar System bodies. The lines represent the typical highest velocities of molecules of various masses. The Jovian planets have high escape velocities and can hold onto even the lowest-mass molecules. Mars can hold only the more massive molecules, and the Moon has such a low escape velocity that even massive molecules can escape.