8. Launch industry

The Moon has minerals, and many proponents of human space exploration figure lunar mining is good enough reason to go back. Gaining experience and mastering the necessary technology might then allow venturous and potentially more lucrative claims to be laid on asteroids, which are rich in metals.

Asteroids, in fact, are thought to contain everything needed to support their own colonies, from water to iron, nickel and cobalt.

The Moon may also have water, frozen in dark polar craters. If so, it could be converted to fuel, turning the Moon into a base for all other solar system exploration.

Critics say it makes more sense to go directly to asteroids and, if desired, Mars.

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