Recent studies are saying the Yellowstone super volcano will erupt sooner than expected.
The studies say the super-eruption will happen in a matter of decades rather than centuries, with an eruption that will blanket most of the US in a thick layer of ash.
If and when that happens, it'll launch the Earth into a volcanic ice age.
Researchers say they are keeping an eye on the volcano and seismologists at the University of Utah are working with geologists in Yellowstone.