Helium

noble gas · lightest elements · space science · invisible

Lighter than air. Helium is so light that it floats up into the sky. That's why balloons filled with helium rise instead of sinking to the ground like balloons filled with regular air.

Made in stars. Most helium in the universe was created during the Big Bang, but stars continuously make new helium by fusing hydrogen together deep in their cores. The Sun and Jupiter contain tons of helium from this process.

Coldest element. Helium has the lowest boiling point of any element, meaning it stays a gas even at temperatures colder than almost anything else on Earth. It's so reluctant to turn into a liquid or solid that it practically refuses to freeze.

Super inert. Helium doesn't react with other elements because it's perfectly happy all by itself. This makes it one of the safest, most stable gases we know of.

Element number 2. Helium is the second element on the periodic table, right after hydrogen. Only hydrogen is more abundant in the observable universe.