Going, Going, Gone?

This month, more than 50 million people will watch as giant balloons float through New York City in the annual Macy’s Thanksgiving Day Parade. Most of the balloon characters, from Pokémon’s Pikachu to Goku from Dragon Ball, tower an impressive five to six stories tall. What keeps these massive structures floating? The balloons are filled with helium (He), an odorless, colorless gas that’s lighter than air.

Each year, the Macy’s parade uses enough helium to fill more than 100,000 party balloons! The gas isn’t prized just for its ability to keep things aloft, however. It also has many important uses in science, technology, and medicine. But in recent years, high demand and low supply have made helium harder to come by. “Helium is a nonrenewable resource,” says Moses Chan, a physicist at Pennsylvania State University. People are using the gas faster than it can naturally be replaced. That has some worried: Are we on the verge of running out of helium? Science World spoke with experts to find out.

This month, giant balloons will float through New York City. More than 50 million people will watch the yearly Macy’s Thanksgiving Day Parade. The balloons look like characters, from Pokémon’s Pikachu to Goku from Dragon Ball. Most of them are five to six stories tall. What keeps these giant structures floating? The balloons are filled with helium (He). This odorless, colorless gas is lighter than air.

Each year, the Macy’s parade uses a huge amount of helium. It would fill more than 100,000 party balloons! The gas is prized, but not just because it makes things float. It also has many important uses in science, technology, and medicine. But in recent years, helium has been harder to get. That’s because of high demand and low supply. “Helium is a nonrenewable resource,” says Moses Chan, a physicist at Pennsylvania State University. People are using the gas faster than it can naturally be replaced. That has some worried. Are we close to running out of helium? Science World spoke with experts to find out.

Helium is best known for its use in balloons, but they account for just 8 percent of helium used each year. Helium is mostly used for more practical purposes (see Beyond Balloons). For example, helium plays a big role in rocket launches. Engineers pump helium through rocket engines to remove chemical residue from them before liftoff and after landing. Residue in engines could combust unexpectedly, endangering astronauts and technicians. But because helium is inert, it won’t react with these chemicals.

Helium also has the lowest condensation point of any element. It turns from a gas to a liquid at a frigid -269°C (-452°F). Because liquid helium is so cold, it’s used to keep magnets in physics equipment cool. “Scientists at every research university use helium to do experiments at low temperatures,” says Chan. Helium is also used to chill magnets inside magnetic resonance imaging (MRI) machines. Doctors depend on these scanners to take pictures of the inside of people’s bodies to diagnose medical conditions.

Two years ago, an MRI machine belonging to Stanford Hospital and Clinics in California broke, releasing the liquid helium inside. It quickly turned into a gas. “As the helium boils off, you can actually see a cloud of it floating away,” says Shreyas Vasanawala, the director of MRI at the hospital. Without the gas, doctors couldn’t run tests on patients. It took weeks to get the helium needed for the machine to work again.

Helium is best known for its use in balloons. But just 8 percent of helium used each year goes to balloons. Helium is mostly used for more practical purposes (see Beyond Balloons). For example, helium plays a big role in rocket launches. Engineers pump helium through rocket engines before liftoff and after landing. This removes leftover chemicals, which could suddenly catch fire. That would put astronauts and technicians in danger. Helium is inert, so it won’t react with these chemicals.

Helium also has the lowest condensation point of any element. It turns from a gas to a liquid at an extremely cold -269°C (-452°F). Because liquid helium is so cold, it’s used to keep magnets in physics equipment cool. “Scientists at every research university use helium to do experiments at low temperatures,” says Chan. Helium also cools magnets inside magnetic resonance imaging (MRI) machines. Doctors use these scanners to take pictures of the inside of people’s bodies. That helps them diagnose medical conditions.

Two years ago, an MRI machine broke at Stanford Hospital and Clinics in California. The liquid helium inside got released. It quickly turned into a gas. “As the helium boils off, you can actually see a cloud of it floating away,” says Shreyas Vasanawala, the director of MRI at the hospital. Doctors couldn’t run tests on patients without the gas. It took weeks to get more helium so the machine could work again.

Although helium is the second-most-common element in the universe after hydrogen (H), little is present on our planet. Helium has a lower density (mass per volume) than air, so any helium in Earth’s atmosphere drifts up and disperses in the upper atmosphere. Some helium even ends up in space and is lost forever.

To find helium on Earth for commercial use, people look for the gas trapped in underground rock formations. But even these pockets of hidden helium are hard to come by. A helium atom has the smallest radius of any element—about 0.2 nanometers, or roughly 1/250,000 the width of a human hair. That allows the gas to escape through tiny cracks in rock. For the gas to accumulate underground, it has to become stuck beneath hard, impermeable rock. This type of rock lacks holes that gases or liquids can pass through.

Helium is the second-most-common element in the universe, after hydrogen (H). But not much helium is on our planet. It has a lower density (mass per volume) than air. So helium in Earth’s atmosphere drifts up and spreads out in the upper atmosphere. Some helium even ends up in space. Then it’s lost forever.

So where do people find helium to use on Earth?  They look for it trapped in underground rock formations. But these pockets of hidden helium are hard to find. A helium atom has the smallest radius of any element, about 0.2 nanometers. That’s about 1/250,000 as wide as a human hair. So the gas can escape through tiny cracks in rock. Helium builds up underground only if it becomes stuck under hard, impermeable rock. This type of rock lacks holes, so gases or liquids can’t pass through.

In the past, helium used in America was sourced much closer to home. “More than 90 percent of the world’s helium supply used to come from the U.S.,” says Kornbluth. There was also a large backup supply at the Federal Helium Reserve—an underground storage facility located near Amarillo, Texas.

The U.S. government began collecting large amounts of helium for military use and space exploration in the 1960s. But by the 1990s, massive stockpiling of helium seemed like an unnecessary expense. So Congress passed a bill requiring the Federal Helium Reserve to sell off its helium by 2021. Today, the reserve contains about 170 million cubic meters (6 billion cubic feet) of helium, compared with more than 850 million cubic meters (30 billion cubic feet) it held a few decades ago. The reserve still sells helium. But the supply is going fast.

“We’re phasing out so private companies can take the lead,” says Samuel Burton, a manager at the Federal Helium Reserve. Several businesses are looking into extracting helium in Utah, Colorado, Arizona, and New Mexico. In the meantime, though, there’s concern there won’t be enough of the precious gas to go around. Rising prices are already affecting science labs, hospitals, and technology companies that depend on helium. It’s even made blowing up balloons more expensive!

But don’t worry. Kornbluth predicts the shortage will end by 2021, or sooner. “With a number of new projects in the works,” he says, “helium availability will improve fairly soon.”

In the past, helium used in America was found much closer to home. “More than 90 percent of the world’s helium supply used to come from the U.S.,” says Kornbluth. There was also a large backup supply at the Federal Helium Reserve. This underground storage facility is near Amarillo, Texas.

The U.S. government began collecting large amounts of helium in the 1960s. They wanted it for military use and space exploration. But that changed by the 1990s. Holding all of that helium seemed like an unnecessary expense. So Congress passed a bill. It required the Federal Helium Reserve to sell off its helium by 2021. Today, the reserve contains about 170 million cubic meters (6 billion cubic feet) of helium. A few decades ago, it held more than 850 million cubic meters (30 billion cubic feet). The reserve still sells helium. But the supply is going fast.

“We’re phasing out so private companies can take the lead,” says Samuel Burton. He’s a manager at the Federal Helium Reserve. Several businesses are looking into producing helium in Utah, Colorado, Arizona, and New Mexico. But for now, people are concerned. Will there be enough of the precious gas to go around? Science labs, hospitals, and technology companies depend on helium. Rising prices are already affecting them. Blowing up balloons has even gotten more expensive!

But don’t worry. Kornbluth expects the shortage to end by 2021, or sooner. “With a number of new projects in the works,” he says, “helium availability will improve fairly soon.”