All About Helium

Podcast Transcript

Sitting at the far top right of the periodic table is the element helium.

Helium is the second-lightest and second-most abundant element in the universe. It is also an inert gas that doesn’t form molecules with anything.

It has extremely few uses and, despite its cosmic abundance, is very hard to find on Earth.

Yet in the future, it might become one of the most valuable substances in the world.

Learn more about Helium, its discovery, its uses, and its potential future on this episode of Everything Everywhere Daily.

Helium is in many respects the oddest element on the periodic table.

It has an atomic number of two with two protons in its nucleus. It is an inert gas with both electrons in its first shell filled.

Helium has two stable isotopes. The most common isotope, by far, is Helium-4, which has two neutrons in the nucleus. Helium-4 constitutes 99.9998% of all Helium.

The other isotope is Helium-3, which has only one neutron. It constitutes 0.0002% of all Helium. Despite the incredibly small amount of Helium-3, it is extremely important, as we’ll see in a bit.

Helium is created via the fusion of hydrogen, which is the primary form of fusion in stars. As such, Helium is the second most abundant element in the universe, with 24% of all the elemental mass in the universe.

There is twelve times more helium by mass than all the other heavier elements in the universe combined.

Helium has the lowest boiling point of any element, at 4.2 K ?or ?268.9 °C or ??452.070 °F.

At normal pressures, Helium cannot freeze. However, when pressures are increased to about 25x atmospheric pressure and temperatures are close to absolute zero, it can become a solid.

Liquid helium exists in a bizarre quantum state known as superfluidity, allowing it to flow without friction, climb walls, and escape containers through microscopic gaps.

Despite the abundance of helium in the cosmos, there is shockingly little of it on Earth.

Because it is inert, there is no helium chemically bound in rocks. Any helium that reaches the atmosphere will rise and escape into space.

The story of helium’s discovery is one of the strangest in the history of chemistry because it was first found not on Earth, but in the Sun.

Helium’s history begins during the solar eclipse of August 18, 1868, when French astronomer Pierre Jules César Janssen traveled to India to study the Sun’s chromosphere using a spectroscope.

By observing sunlight passed through a prism, he expected to see known spectral lines produced by elements such as hydrogen. Instead, he found a bright yellow line that did not match any earthly element. He reported the anomaly immediately.

Unbeknownst to him, English astronomer Norman Lockyer independently observed the same unexplained line. Because spectroscopic lines were reliable signatures of chemical identity, and this line matched nothing catalogued, Lockyer concluded that it must represent an element unknown on Earth.

He coined it “helium,” derived from the Greek helios, meaning Sun, and proposed the remarkable idea that the Sun contained an element humanity had never encountered.

Although helium was thus “discovered” in the sky, no one knew whether it truly existed on Earth. The race to find it took nearly thirty years. In 1881, Italian physicist Luigi Palmieri detected unusual spectral features in gases emitted by Mount Vesuvius, but the evidence remained inconclusive.

Terrestrial confirmation finally came in 1895 when Scottish chemist Sir William Ramsay treated the uranium mineral cleveite with acid to isolate the gases it released.

Among them, he found a light gas that produced the exact same yellow spectral line seen in the solar observations. Ramsay had effectively captured helium in a test tube. Around the same time, Swedish chemists Per Cleve and Nils Langlet also extracted helium from cleveite, confirming Ramsay’s findings independently.

While most of the helium in the universe is produced via fusion of hydrogen, there is another method by which it is created: radioactive decay.

When a radioactive isotope undergoes alpha decay, it ejects two protons and two neutrons from the nucleus, or a helium nucleus.

The decay of uranium and thorium is how most of the helium on Earth was created.

As almost all radioactive decay occurs below the surface, helium can slowly migrate upward over time and accumulate in pockets of natural gas.

This is why nearly all helium extracted today comes from natural gas fields. Some of the richest deposits, like those in the United States’ Great Plains, contain concentrations high enough to justify separating helium from methane and other components through cryogenic processing.

Helium’s uses are far broader and more strategically important than most people realize. Because it is inert, non-toxic, non-flammable, extremely light, and capable of reaching the lowest boiling point of any element, it fills a set of industrial and commercial niches that almost no other substance can.

One major application is in cryogenics, where liquid helium’s ultra-low temperature is essential for cooling superconducting magnets. This makes it indispensable for MRI machines, many types of particle accelerators, magnetic resonance research, and some quantum computing systems.

Its unique properties also make it a critical coolant in certain nuclear reactors and in low-temperature physics experiments that study phenomena near absolute zero.

Helium plays an important role in manufacturing and materials science. Because it is inert and does not react chemically, it is used as a shielding gas in arc welding, particularly for aluminum and other metals that oxidize easily.

Semiconductor fabrication also relies on helium to create controlled atmospheres, cool components, and purge systems. Fiber-optic cable production requires helium to prevent imperfections in the glass structure.

In aerospace and rocketry, helium is used to pressurize fuel and oxidizer tanks, purge lines, and provide stable, non-reactive environments. Its reliability under extreme conditions has led to its use in virtually every major space program since the early days of rocketry.

Helium also has a role in deep-sea diving, where mixtures such as heliox allow divers to breathe safely at depths where nitrogen becomes narcotic.

There are numerous commercial uses as well.

It aids in the production of specialized scientific instruments, in gas chromatography, and in controlled-atmosphere environments for preserving sensitive materials. Even in medical treatments, helium-oxygen mixtures can support patients with respiratory issues because helium’s low density reduces airway resistance.

It is used in leak detection systems because helium’s tiny atoms can escape even the smallest gaps and are detected at extremely low concentrations.

Most people are familiar with Helium’s filling balloons and blimps. Because it is far safer than hydrogen, it is the preferred lifting gas.

Most of you have probably experienced the effect of helium when you inhale it. It will temporarily make your voice sound like a cartoon character.

The reason why this happens is pretty straightforward.

People speak in a high-pitched voice after inhaling helium because the gas dramatically changes how sound travels through the vocal tract. The physics is simple: helium is much less dense than air, and sound waves move much faster through it.

That change in sound speed alters the resonant frequencies of the cavities in your mouth, throat, and nasal passages.

Helium is safe insofar as it isn’t toxic and can’t interact with anything in your body, but if you inhale too much, it can displace oxygen in your lungs.

Because demand for helium has increased with the rise of high-tech uses such as semiconductor manufacturing and MRIs, and because the supply of helium is very finite, there have been growing concerns about a helium shortage.

Unlike oil or gas, the supply of helium can’t just be ramped up if the price increases. Only a few natural gas fields have enough helium to extract it economically.

When these fields decline, or when natural gas markets shift for unrelated reasons, helium supply tightens. The industry also struggles with the long lead times required to build extraction, purification, and storage infrastructure.

Combined with occasional geopolitical disruptions and maintenance shutdowns at major processing plants, the global market has experienced repeated “helium crises” over the past two decades, leading to price spikes and shortages that hit hospitals and research labs hardest.

The United States’ Strategic Helium Reserve was created to buffer exactly this kind of volatility. Established in 1925, it had nothing to do with semiconductors or medical imaging. The federal government wanted a secure supply of helium for military airships.

Over time, Congress expanded the reserve, leading to the creation of the vast Bush Dome storage facility near Amarillo, Texas.

This facility became a global stabilizer because it allowed the US to stockpile enormous quantities of crude helium and release it into the market during shortages. For decades, it was the world’s largest single source of helium and effectively the backbone of global helium supply.

The reserve, however, also created distortions.

Under the 1996 Helium Privatization Act, Congress ordered the government to sell off the reserve to recoup its debts, forcing helium onto the market at artificially low prices.

Cheap helium discouraged investment in new extraction and encouraged wasteful uses, while also making the industry dependent on a resource that was being intentionally depleted. As the reserve was gradually depleted and privatized, the market lost its stabilizer.

There is one other thing about helium that I alluded to at the start of the episode. It might be the most critical use of helium in history and has the potential to reshape society.

Nuclear fusion and quantum computing both require helium. The problem is, it requires Helium-3.

The Isotope of helium, which represents only 0.0002% of all Helium.

Many of the most promising quantum computing platforms, including superconducting qubits, topological qubits, and some spin-based systems, must be operated at temperatures where thermal noise is essentially eliminated

When mixed with helium-4, helium-3 allows the creation of dilution refrigerators, the only practical devices capable of reliably reaching temperatures in the millikelvin range, just thousandths of a degree above absolute zero.

Helium-3 is attractive in fusion because when it fuses with deuterium, it produces almost no neutrons, releasing its energy mainly as charged particles.

That means, in principle, a He-3 fusion reactor could generate power with far less radioactive damage, simpler shielding, and the possibility of directly converting particle energy into electricity.

However, there is a problem. Helium-3 is really, really rare.

Outside of exotic particles like antimatter, which can only be created a few atoms at a time, Helium-3 is the most valuable elemental substance on Earth.

A kilogram of it can sell for as much as $20 million dollars.

So, if we are going to need more Helium-3, and Helium-3 is just a tiny, tiny fraction of all the Helium produced, and if Helium is already in short supply, where in the world are we going to get the Helium-3 from?

One place we are not going to get it from is Earth. There just isn’t enough. Nor can we really make any.

One place that does have a lot of helium is the Sun, and the Sun throws off a lot of Helium in the solar wind.

However, the Earth’s magnetic field causes most of that to be deflected into space.

So, the best bet for finding Helium-3 would be….the Moon.

Over the course of billions of years, Helium-3 has been ejected from the Sun and has lodged into the lunar regolith on the surface.

Lunar mining of helium-3 would involve collecting and processing the thin layer of regolith in which the isotope has been implanted over billions of years by the solar wind.

Because helium-3 exists only in trace amounts, mining would resemble large-scale surface strip-processing rather than deep excavation. Robots or bulldozer-like vehicles would scoop up vast quantities of lunar soil and deliver it to a processing plant, where the regolith would be heated to several hundred degrees Celsius to release trapped gases.

Those gases would then be captured, cooled, and separated so that the tiny fraction of helium-3 can be isolated from far more abundant helium-4 and other volatile gases.

At $20 million per kilogram, Helium-3 mining might make a lunar base cost-effective.

Helium is a lot more than party balloons. Its inertness, its lightness, and its low boiling point make it uniquely suited for many tasks.

…and it is entirely possible that helium will become even more important in the future as new technologies exploit the properties of the Helium-3 isotope.