Well, the last great era of exploration was driven by profit-seeking, during which Columbus discovered the Americas. The backers of the various explorers expected returns on their investment.

I suspect the next great era of exploration (this time into the last frontier that is space) will also be profit-driven. What I want to know is, what does the moon, Mars, and other relatively close celestial bodies offer that has the potential to justify the investment? What potential (financially profitable) uses have been proposed?

Arthur C. Clarke saw an Earth in the year 2001 that had Pan Am shuttles to LEO space stations and moon bases. I wonder what justification he has for those! :-)