This Moon was Made for Mining (Helium-3)

The 2009 indie film Moon features Sam Rockwell as an employee (named Sam) of the fictional Lunar Industries, a mining corporation back on Earth.

Just wrapping a three-year solitary stint on the moon, Sam is charged with overseeing the automated harvesters which extract helium-3 from the lunar regolith. Canisters of the harvested helium-3 are then sent to Earth to be used to generate fusion energy.

Much of the film deals with Sam's growing personal crisis as he finds out a few unpleasant things about his employer. The movie's premise is technically science fiction, but the notion of mining the moon for valuable natural resources that are in short supply on Earth is closer to reality than you might think.

As Discovery News reports, thanks to a critical shortage last year, the price of the isotope helium-3 has skyrocketed from $150 per liter to $5,000 per liter.

Helium wasn't technically "discovered" on Earth until about 1895, despite being abundant in the universe. Almost all of the global supply of helium is located within 250 miles of Amarillo, Texas; it's distilled from accumulated natural gas and extracted during the refining process.

Since the 1920s, the US has considered its helium stockpile as an important strategic natural resource, amassing some 32 billion cubic feet in an underground bunker in Texas, but for several years now, it's been selling off that stockpile bit by bit to interested industrial buyers.

Helium is used for arc welding and leak detection, mostly, although NASA uses it to pressurize space shuttle fuel tanks. Liquid helium cools infrared detectors, nuclear reactors, and the superconducting magnets used in MRI machines, too. The fear is that, at current consumption rates, that underground bunker will be empty within 20 years, leaving the earth almost helium-free by the end of the 21st century. This could be bad for US industry.

It also bodes ill for the prospect of fusion using helium-3, a rare helium isotope that is missing a neutron. Physicists have yet to achieve pure helium-3 fusion, but if they did, we'd have a clean, virtually infinite power source. Or so the theory goes.

And that's where the moon comes in. The moon's lunar soil is chock-full of helium reserves, thanks to the solar wind. In fact, every star emits helium constantly, suggesting that one day, spaceships will carry on a brisk import and export trade to harvest this critical element - assuming we can figure out how to make such a process economically viable.

But helium-3 isn't the only resource the moon might have to offer. It could also be a source for rare earth elements, such as europium and tantalum, which are in high demand on Earth for electronics and green energy applications (solar panels, hybrid cars), as well as being used in the space and defense industries.

China is the largest exporter of rare earth elements, but there are growing concerns over supply vulnerability as China drastically reduces its rare earth exports. Scientists know that there are pockets or rare earth deposits on the moon, but as yet they don't have detailed maps of those areas. Potassium, phosphorus and thorium are other elements that lunar rocks have to offer a potential mining venture.

And there's more! In 2009, NASA bombed the moon - part of its Lunar CRater Observation and Sensing Satellite (LCROSS) mission - and observed grains of water ice in the remnants of the resulting plume, as well as light metals such as sodium and mercury, and volatile compounds like methane, ammonia, carbon dioxide, carbon monoxide and hydrogen. This implies that the moon is chemically active - via a process called "cold grain chemistry" - and also has a water cycle. Where you have water ice, you have a potential mother lode for lunar prospecting of hydrogen.

Of course, we're talking about huge capital expenditures just to set up a mining base camp on the moon, and the economies of scale might not be there. If the benefits don't outweigh the costs, we might never see bona fide lunar prospecting. But it's a possibility that the US - not to mention China - is taking very seriously.

Image credit: NASA