Helium isn’t just for party balloons.

It’s a critical ingredient in a lot of modern technology, from the James Webb Space Telescope, to the equipment for laser eye surgery! But there’s a weird downside: Despite being a gas that doesn’t contain any carbon in it, it’s got a pretty large carbon footprint.

As a result, scientists and entrepreneurs are on the hunt to find the world’s first “green helium”. [♪ INTRO] While helium might seem ubiquitous now, we had no idea how to get to it until 1905 after a natural gas well was discovered in the small town of Dexter, Kansas. To celebrate their good fortune, the Dexterians planned to ignite the well with a burning bale of hay. But those plans fell through when the gas refused to catch fire.

That caught the attention of some chemists from the University of Kansas, who brought a few samples back to the lab. As it turned out, the well wasn’t spewing out much methane, but it was emitting a heck of a lot of nitrogen, and yes, some helium, as well. Before that discovery, the only place we knew had ample supplies of helium was the Sun.

Fast forward to today, and almost all of the world’s helium supply is still harvested the same way…as a “waste product” of natural gas drilling. In other words, helium extraction has always been accompanied by quite a lot of carbon emissions. Which is something we should probably try to update.

The good news is, we already know that underground pockets of methane-free helium exist. They’re just incredibly rare. And a 2023 study out of Oxford was able to shed some light on how they form, giving us a big helping hand in this gaseous game of hide and seek.

See, Earth’s helium is produced as a natural byproduct of radioactive elements beneath the crust. Stuff like uranium and thorium undergoing radioactive decay. And because they’re so darn light, the resulting helium atoms gradually just float up through the crust.

While some leak all the way up into the atmosphere and get lost to outer space, others come to rest against a stubborn rock layer that doesn't let them pass. Insert the obligatory Gandalf reference, here. Now, it turns out that just like helium, nitrogen also gets released from deep within the Earth’s crust.

And as it moves upwards, it gathers in really high concentrations over hundreds of millions of years. As a result, this nitrogen can actually carve out gas bubbles within the pores of a rock layer. And when it does so, it brings helium along for the ride.

The result is a subterranean field helium and nitrogen without all the greenhouse gas. By shedding light on how much of each gas they should expect to see fizzling out of a promising site, the Oxford researchers think they may have developed a powerful tool for pinpointing hidden helium fields. But there are already quite a few startups scouring the Earth, or at least North America and Africa, with dreams of harvesting the world’s first “green helium”.

One of the most promising spots seems to be the Rukwa Basin in Tanzania, where some underground springs might have helium concentrations up 18x higher than natural gas fields. While all of these expeditions are still in very early stages, it’s safe to say that wherever we find the first big pocket of green helium, we can use some of it to fill a few party balloons. Thank you for watching this episode of SciShow.

And thanks especially to our Patreon subscribers, who just help us keep the lights and cameras on to capture all this action. To learn how you can support the channel, and all the perks we have to say thank you, head on over to Patreon.com/SciShow. [♪ OUTRO]