A computer simulation of Pluto’s massive crater demonstrates how thick the liquid ocean hiding beneath could be. Apparently, under Pluto’s icy shell, scientists believe that there could be more than 100 kilometers of liquid water buried deep.

In their study published in the journal Geophysical Research Letters, this secret ocean could contain a salt content similar to that of the Dead Sea. The research focused on the Sputnik Planum, a 900-kilometer wide icy basin on Pluto, which was most likely created by a 200-kilometer or larger asteroid.

After the asteroid impact, the basin was partially filled by nitrogen but the layer of the nitrogen ice was not thick enough to make Sputnik Planum as it is now. So the team says that the only explanation for this is that the rest of the mass could be generated by water beneath the surface.

The water could have risen after Sputnik Planum got hit. Overall, the scientists estimate that the water layer could be as thick as 100 kilometers and has a salinity of about 30 percent.

“This scenario requires a liquid ocean,” points out the study’s lead researcher, geologist Brandon Johnson of Brown University. “We wanted to run computer models of the impact to see if this is something that would actually happen. What we found is that the production of a positive mass anomaly is actually quite sensitive to how thick the ocean layer is. It’s also sensitive to how salty the ocean is because the salt content affects the density of the water.”

The lead researcher hopes that NASA’s New Horizons spacecraft would provide them with more pictures that can confirm a hidden ocean beneath the surface of Pluto. Other collaborators of the study include Timothy Bowling of the University of Chicago and Alexander Trowbridge and Andrew Freed from Purdue University.