What potential resources could be mined from asteroids? According to Zubrin, is it financially feasible to do so?

Title: The Case for Space: How the Revolution in Spacecraft Opens Up a Future of Limitless Possibility

After returning to the Moon, what are the potential “next steps” that Zubrin describes in his book?

What potential resources could be mined from asteroids? According to Zubrin, is it financially feasible to do so?

Zubrin discusses the possibility of use He3 as fuel for missions to the outer solar system. According to Zubrin, where is the best place to mine He3, and why. Briefly describe the process needed to do so.

Describe the steps that would be needed to terraform Mars. What about a hot world like Venus? Comment on which would require more time and resources, and why?