WASHINGTON, July 2 (Xinhua) -- Ocean within Saturn's largest moon, Titan, could be as salty as Earth's Dead Sea, U.S. space agency NASA said Wednesday.
The findings, published in the U.S. journal Icarus, were based on gravity and topography data collected by NASA's Cassini spacecraft during its repeated flybys of Titan in the past 10 years.
Using the Cassini data, researchers created an improved model structure for Titan, including its icy shell and the ocean that lies beneath.
The model showed that a relatively high density was required for Titan's ocean in order to explain the gravity data. That indicated the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur, sodium and potassium.
NASA said in a statement the density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth.
"This is an extremely salty ocean by Earth standards," said the paper's lead author, Giuseppe Mitri of the University of Nantes in France. "Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past."
Cassini data also indicated the thickness of Titan's ice crust varies slightly from place to place.
The researchers said this can best be explained if the moon's outer shell is stiff, as would be the case if the ocean were slowly crystalizing and turning to ice. Otherwise, the moon's shape would tend to even itself out over time, like warm candle wax.
"This freezing process would have important implications for the habitability of Titan's ocean, as it would limit the ability of materials to exchange between the surface and the ocean," NASA said.