A new investigation found that a global ocean is hidden under the crust of ice enveloping the Saturnian moon, Enceladus. This new discovery was drawn after experts analyzed the data collated by the Cassini spacecraft of the National Aeronautics and Space Agency (NASA).
According to previous investigations, a body of water that is shaped like a lens is present beneath the South Pole of the geologically active moon. However, the possibility that the sea is extended throughout the moon was not clearly established as per Cassini's gravity information gathered during its numerous close encounters with the south pole. In the new investigation using a separate set of evidence based on the images provided by the spacecraft, this possibility has been confirmed.
The experts examined images of the Enceladus that were captured by the Cassini spacecraft over a period of seven years. The precise positions of the moon's features, mostly craters, were intricately determined through hundreds of photos to accurately measure the extremely detailed changes in the rotation of the moon.
The researchers discovered that the Enceladus wobbles in a particular way as it orbits around Saturn. This magnitude exhibited by the moon is said to be possible only if its icy outer shell does not extend up to the core. Therefore, the observation made by the scientists signifies that a global ocean is indeed present. Also, the imperfect spherical shape of the moon, as well as its inconsistent speed of rotation as it orbits the planet drives Saturn to rock Enceladus back and forth during its orbit.
The group of experts also incorporated their wobble data into a different set of models that demonstrates how the moon may possible be formed inside. The models included those that represent the moon to have an all-out icy composition from the surface to the core.
The results of the study, published in the journal Icarus, showed that tiny water vapors, icy substances and simple organic molecules that the Cassini has observed all came from a massive body of water.
"This was a hard problem that required years of observations," said Peter Thomas, the study lead author and a member of the Cassini imaging team at the Cornell University. Calculation driven from a multidisciplinary approach were also imperative but now he said that the team is confident that they were finally able to get it right.
The reason why the Enceladus does not freeze all the way down to its core is still unknown. Further researches involving different areas of study are recommended by the researchers to solve this mystery and confirm the possibility that Saturn's gravity is generating tidal forces that are keeping its moon warmer than what has been perceived in the past.
