As announced newscientist.com, Wanying Kang of the Massachusetts Institute of Technology (MIT) and her colleagues wanted to determine what the clean, bright ice covering Enceladus’ surface might indicate about the ocean below.

Samples of geyser-like jet water taken from the surface of Enceladus by the Cassini spacecraft have previously shown that the icy moon contains organic matter that could support life.

Considering the water beneath Enceladus’ ice was a logical next step in determining its habitability, Kang says.

The team created a theoretical model that explains how ocean salinity, ocean currents and ice geometry interact on planets or moons, and then refined it to better reproduce the properties of Enceladus’ ice, they write. newscientist.com.

The researchers found that salty subterranean oceans correspond to thicker ice at the planet’s poles than at its equator, and vice versa—where the ice is thinner, the water is presumably less salty.

On the planet Enceladus, the ice above the poles is thinner than the ice above the equator. Specific thickness variations indicate that ocean salinity can be as high as 30 grams of salt per kilogram of water. By comparison, the salinity of Earth’s oceans is 35 grams of salt per kilogram of water.

The researchers also modeled aspects of the water circulation beneath Enceladus’ ice. These currents are related to differences in water temperature, so understanding them is also important for determining ecosystems, says W. Kang.

The team found that some heat is coming from the ocean floor of Enceladus, indicating that the ocean floor has heat sources. W. Kang says. newscientist.com.

Kang and her team are trying to apply the new model to Jupiter’s moon Europa, which is thought to be saltier than the oceans of Earth and Enceladus. Ultimately, they want to pinpoint the oceans of all the icy moons and planets observed by space missions, to better determine how habitable they are.