Behind hydrogen, helium is the most abundant element in the universe, making up a whopping 25% of its mass. But here on Earth, it's much more rare. The concentration of helium in our atmosphere is 0.00052%, or just over 5 parts per million. That's because just like the balloons it fills, helium wants to rise. Once it hits the air, it floats out of our atmosphere and into space. This is a problem, since helium is essential to a vast array of technologies for its ability to cool things quickly without corroding or combusting: think MRI machines, semiconductors, and cryogenics. Helium is produced by radioactive uranium decay deep within the Earth, where it slowly migrates up to the crust over hundreds of millions of years to sit in deposits until it's released through either tectonic activity or manmade drills. In this way, it's a lot like oil, in that some countries (especially the United States) have larger quantities of it than others, and even though it's created through natural processes, there's a risk we could run out. In fact, some experts predict that at our current rate, we're on track to run out by 2020. Others, however, are more optimistic, saying that because helium is constantly produced through radioactive decay, it can't ever run out. We've collected some awesome videos on this topic. Watch them now to learn more.
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Key Facts In This Video
Helium doesn't explode or corrode, making it perfect for all sorts of uses. 00:16
Helium is the second most abundant element in the universe, but its concentration in our atmosphere is only 0.00053%. 00:52
The US uses half the world's supply of helium and has been selling off its reserves at a rate that will make us run out by 2020. 01:48