Contrary to popular belief, helium is not used only to inflate party balloons. Given that helium is inert, it is used to create nonreactive atmospheres in semiconductor fabrication and in arc welding, for instance. However, the most important industrial application of this noble gas is probably in cryogenics. Liquid helium is used to cool infrared sensors, nuclear reactors, and superconducting magnets (for example, in MRI equipment). Helium is also used for leak detection, and as a gain medium in He-Ne lasers.
Helium is the 2nd most abundant element in the universe, right after hydrogen. Helium is produced in stars by nuclear fusion:
[ source ]
On Earth, the helium-4 isotope is by far the most abundant, a byproduct of millions of years of alpha decay of uranium and thorium (note that the nucleus of helium-4 is the same as the one of an alpha particle). Helium is extracted during the refining of natural gas. If it’s not extracted during this refining process, it soars off and is forever lost.
Since nuclear fusion technology is still decades away and given that alpha decay is an extremely slow process, industrial production of helium is indeed very far from becoming a reality. We will need to keep extracting helium from natural gas reserves. The problem is that helium reserves may be depleted within the next decade [1][2]. Once that happens, where will we get the helium demanded by high-tech industries?
If helium becomes a sought-after commodity, then the same companies that extract natural gas will have an economic incentive to extract helium as well, instead of letting it escape to the atmosphere. However, helium is a non-renewable resource. Sooner or later, we will deplete the reserves that have built up over millions and millions of years.
The Sun produces colossal amounts of helium by nuclear fusion. In fact, helium is named after Helios, the Greek god who personified the Sun (helium was first found in the Sun). Harvesting helium from the Sun is impossible, however. At least directly. A possibility would be to harvest helium-3 (to serve as fuel for fusion reactors) from moon rocks [3][4][5], where it can be found due to billions of years of bombardment by the solar wind. If the idea of mining the Moon sounds insane to you, please note that Harrison Schmitt (geologist and Apollo 17 astronaut) is one of the proponents.
Is the Moon the El Dorado of helium-3? I don’t know, but I have heard rumors that India and China are developing robotic systems to harvest helium-3 from moon rocks. It seems that Space is the next frontier in the race for natural resources. What next? Will we be mining asteroids to extract platinum for fuel cells?
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References:
[1] Emily Jenkins, A Helium Shortage?, Wired Magazine, Aug. 2000.
[2] Laura Deakin, The coming helium shortage, Chemical Innovation, June 2001.
[3] Harrison Schmitt, Mining the Moon, Popular Mechanics, Oct. 2004.
[4] John Lasker, Race to the Moon for Nuclear Fuel, Wired Magazine, 2006.
[5] Mark Williams, Mining the Moon, Technology Review, Aug. 2007.
