Some 390 million miles away from Earth is a small moon of Jupiter named Europa. The most astonishing fact about Europa is the watery ocean splashing underneath the moon's icy, outer crust. Even with its size, which is four times smaller than Earth, Europa is believed by researchers to hold even more water than all of Earth’s oceans combined. For instance, if you could form a huge sphere with all of the water on Europa, that sphere would be nearly 1,090 miles across — 300 miles bigger than if you did the similar thing with all of the water on Earth. That’s a lot of water for such a small moon, and it makes for a very deep and huge potential environment for alien life.
How deep? Researchers estimate that some portions of Europa's ocean could stretch over 100 miles under the thick outer surface. That's 16 times deeper than the deepest regiom on Earth, which is at the bottom of the Mariana Trench in the western Pacific. To give you an awareness of this, the people who run the YouTube channel “5 hours ahead” have prepared this remarkable short GIF (Shown Above) that's a struggle to stop watching.