Scientists have long suspected there to be a hidden ocean under Enceladus, a moon of Saturn, and a new report all but confirms their suspicions.

By measuring wobbles in Enceladus’ orbit, scientists have determined that an entire ocean exists under the moon’s icy surface. The picture above best illustrates what that ocean might look like if you were to peel back Enceladus’ different layers. The new breakthrough concludes seven long years of study, and proves Earth isn’t the only place in our solar system with liquid water. It also shows just how similar Enceladus is so Jupiter’s moon Europa.

“If the surface and core were rigidly connected, the core would provide so much dead weight that the wobble would be far smaller than we observe it to be,” explained Matthew Tiscareno, a Cassini scientist. “This proves that there must be a global layer of liquid separating the surface from the core.”

Last year, scientists theorized Enceladus had an interior reservoir of water, but they never thought there would be so much of it. The findings come on the heels of observations made by Cassini in 2014, which saw water vapor and water ice plumes near the moon’s south pole. Scientists believe the ocean could be as deep as six miles, and lay beneath the moon’s ice shell, which is estimated to be about 25 miles thick.

Cassini is set to make more observations of Enceladus later this year before it wraps up its mission in 2017.