This Metal Glows Red-Hot for 100 Years — On Its Own ☢️ #scienceshorts #facts #science #physics

Added: 2026-05-17

[00:00:00]This metal is glowing redhot. Nothing is heating it, and it'll stay this hot for a hundred years. It's plutonium 238, a radioactive isotope.

[00:00:11]As it decays, it releases energy as heat constantly.

[00:00:16]With no fuel, no flame, and no off switch. A single piece the size of a marshmallow gives off enough heat to glow visibly. And it does this for decades. Every 88 years, half of it has turned into uranium.

[00:00:31]So, the heat slowly fades.

[00:00:33]But slowly.

[00:00:35]After a century, it's still warm enough to power a machine.

[00:00:38]That's why NASA [music] uses it. Solar panels stop working far from the sun or when they get covered in dust. But a chunk of plutonium 238 just [music] keeps going.

[00:00:49]Right now, on Mars, there's a piece of metal glowing in the dark.

[00:00:53]It'll still be glowing when your great-grandchildren are old.