At such temperatures atoms are stripped down to their electrically charged components, so the helium created by fusion remains within the magnetic bottle.

ECONOMIST: Nuclear fusion

"It is dubious whether it will ever be economically viable even if nuclear fusion works commercially or if helium-3 is a better option than other elements available on earth, " he told CNN.

CNN: Mining the moon for a nuclear future

But the Moon is a source of rare earth elements, as well as Helium-3, a possible future fuel for nuclear fusion reactors (if we ever actually invent them).

FORBES: Richard Branson Wants a Population on Mars. Here's How He Can Create It.

Some visionaries think that this helium might find a market on Earth, though its main use would be in fusion reactors that do not yet exist.

ECONOMIST: Spaceflight

Research at the Fusion Technology Institute at the University of Wisconsin has also suggested that the process of mining helium-3 would produce other minerals to support space settlements.

CNN: Mining the moon for a nuclear future

Energy resources that can be harvested in space for the benefit of Earth include helium-3 that occurs in abundance on both the Moon and asteroids and is ideal for new small fusion plants, as well as solar energy that can be collected and transmitted in concentrated form to Earth.

FORBES: Move up http://i.forbesimg.com t Move down