Ever been mesmerized by the swirling colors of Grand Prismatic Spring and wondered what fuels that otherworldly boil? It turns out that beneath the wild expanse of Yellowstone National Park lies one of the most closely watched volcanic systems on Earth.

A recent study discovered the exact location of the Yellowstone supervolcano's magma cap -- and hints at when it may erupt.

Yellowstone's supervolcano appears to have a magma cap that vents pressure and reduces the chances of a massive eruption happening anytime soon.