The world is beset with energy problems. Fossil fuels are being depleted, gasoline prices are growing, and there is great concern that our increasing carbon emissions will raise global temperatures uncontrollably. With rapid industrialization occurring in India and China – home to more than 2.3 billion people – these problems will just become worse.

However, there is one fuel source that could save the world from a dark future. A fusion nuclear reactor powered by helium-3 (He3) could provide enormous amounts of power without any harmful carbon emissions or the radioactive byproducts created by today's nuclear fission reactors.

There are only two problems. Nobody has yet created a nuclear fusion reactor that could run on helium-3. And the Earth has so little helium-3 that you would have to mine the Moon for it. Scientists and engineers are working to solve both problems.

Current power plants use nuclear fission, a process in which uranium nuclei are split apart. This releases energy but it also produces radioactivity and nuclear waste that must be securely stored for many thousands of years.

In nuclear fusion, nuclei are fused together. These reactors use the same energy source that powers the Sun and stars. However, nuclear fusion does not produce the radiation and nuclear waste that is harmful to human life.

Scientists have been working for many decades to try to produce a working fusion reactor. It turns out that destroying nuclei is a lot easier than fusing them together. The process results in a significant loss of energy and is difficult to contain. Scientists have had a difficult time creating a fusion reactor that would put out more energy than it needs to operate.

Scientists are exploring how to develop a fusion reactor that uses helium-3 and deuterium. The process would create normal helium and a proton, which are easy to contain. The process, if it can be perfected, would produce no radiation and virtually no waste.

If scientists can perfect such a reactor, they will need to get fuel for it. Unfortunately, very little helium-3 occurs naturally on Earth. Although helium-3 is abundant in the solar winds emitted by the Sun, the Earth's atmosphere absorbs most of it. The Moon, however, has no atmosphere, so there is abundant helium-3 locked up in the lunar regolith.

Mining the Moon for helium-3 would be no easy task. Miners would need to process about one million tons of lunar soil in order to get 70 tons of helium-3. The fuel would then have to be shipped back to Earth in bulk.

Given the potential of this power source, it's likely that many nations would try to mine the Moon for helium-3 once a working fusion reactor was invented. A new gold rush could occur on the lunar surface later in this century.