It'll never rank up there with turkey and pumpkin pie, but for millions of Americans the Thanksgiving experience just wouldn't be the same without ... helium.
For 364 days of the year, the colorless and odorless gas works quietly behind the scenes, doing jobs like chilling magnets in MRI imaging machines and helping welders protect their work from impurities.
But on Thanksgiving, the lighter-than-air element moves onto a much bigger stage. It's the stuff that makes Snoopy, Spider-Man, Papa Smurf and other huge balloons sail high above the crowd at the Macy's Thanksgiving Day Parade in New York.
Just so we can be properly thankful for the second most abundant element in the universe (it ranks behind hydrogen), we turned for some basic facts to Eric Bass. He is product manager for helium at Linde North America Inc. This week, for the 20th straight year, his company will supply the gas to the parade, which in turn is marking its 88th year.
Where does the parade helium come from?
It forms underground and tends to mingle with natural gas deposits. So when companies extract and process the natural gas, they separate out the helium and sell it to companies like Linde. Helium is shipped worldwide, so the stuff that will pump up Paddington Bear or Pikachu could come from as close as Kansas or Wyoming, or as far away as Qatar, Africa or even Australia.
How does it get to the parade?
First, the gas is chilled to make it a liquid so it's easier to transport. Huge, specialized containers of the stuff are shipped to a plant in Bethlehem, Pennsylvania. Gas floats above the liquid in these containers; this gas is drawn off and compressed. The gas is loaded into heavy steel tubes, and 10 to 12 tubes are put on each of four flatbed trucks. The day before the parade, the trucks drive into Manhattan for the inflating of the parade balloons. Crews fill the balloons with long hoses, topping them off on parade day.
How much helium is needed?
Enough to fill 600,000 to 700,000 Mylar party balloons. But the parade helium is 99.999 percent pure, whereas the stuff in a party balloon might be only 97.5 percent pure.
How big are the balloons?
They come in a variety of sizes. According to Macy's, Snoopy is as tall as a three-story building, as long as 11 bicycles and as wide as five taxi cabs. The big balloons are made up of multiple chambers that are inflated individually.
What happens to the helium after the parade?
It escapes to the atmosphere as the balloons are deflated. In 2008, Linde tried recycling some of the gas by withdrawing it through tubes put into some of the balloons. But Bass said the process was expensive, and there wasn't enough time to recover most of the gas before the streets had to be cleared for traffic.