- [Narrator] With a hard, frozen exterior, Enceladus's surface averages a chilly minus 330 degrees Fahrenheit.

It's one of the coldest places in the Saturn system, an ice world where we'd expect everything to be completely still, frozen, and unchanging.

But in 2005, NASA's Cassini spacecraft traveled to the south pole and discovered that stillness shattered.

It captured explosive jets constantly erupting from the surface.

- So when we first saw those plumes coming out of Enceladus, it was just mind-boggling that to see this tiny world spewing material out, indicating that it was geologically active.

- Discovering the jets at Enceladus's south pole completely changed the way that we see icy worlds.

It changed the way that we see small, icy worlds in particular.

- [Narrator] Giant plumes, far bigger than the moon they erupt from, are an incredible sight.

But how is it possible to have such powerful eruptions on a frozen moon?

Over 660 pounds of water erupt from the surface of Enceladus every second, creating visible eruptions that can thrust up to 6,000 miles into space.

It's called cryovolcanism, cryo from the Greek for cold.

- Cryovolcanism is absolutely volcanism.

When we study the planets, we learn that even though they have different chemistry or slight differences, that these processes are common throughout the planets and volcanism is one of them.

- What is surprising is not only the presence of those jets but their size, the fact that this is an extreme cryovolcanism coming from such a small body.