The ocean across the globe on the frozen moon Saturn Enceladus, which is believed to be at least 30 kilometers deep, could orbit in currents such as those found on Earth say that scientists in a new study; a discovery that could one day help reduce the trace of life on this strong world.
Despite being only 500 kilometers in diameter and with the most reflective body in the solar system due to its thick cover of ice, Saturn’s sixth largest moon, Enceladus, is one of the a few places in our cosmic back garden where life might be present.
Its status as a habitable world was heightened, when in 2008 NASA’s Cassini mission sampled material sent into space by jets firing out of an ocean Enceladus at 400 meters per second (800 miles per hour).
The material, which is a plume that extends hundreds of kilometers into space, was a mixture of water and simple organic chemicals and signified the existence of an underground ocean with unparalleled chemistry and indoor heat.
This deep ocean was thought to be homogeneous and did not move around much except a direct mixture guided by the warmth of the lunar heart.
This also meant that the top of the ocean near the ice shell would be colder – effects that were completely different to the Earth’s ocean which is warmer at the top from the sun’s rays and colder in the sun. the depth near the seabed.
Enceladus also has another strange feature – the poles have thinner ice than the equator; a feature detected by gravity measurements and heat calculations from Cassini, which flew with the tiny frozen ball for the last time in October 2015.
Using the knowledge of the interaction of ice and water to control ocean mixing around Antarctica, a team of researchers with Caltech graduate student Ana Lobo and Andrew Thomson, professor of environmental science and engineering, ran several models computer try why this might be so.
Their results showed that the flow of salt-filled urine from a pole to a equator could account for the ice structure seen on Enceladus.
Salt water can affect the flow of the ocean when it freezes, as it releases the salts, making the surrounding water heavier, causing it to sink. The opposite occurs in regions of melting.
If Enceladus churned out oceans similar to those on Earth, pole-to-equatorial rotation would affect heat and nutrient circulation causing depletions of thin ice at the poles due to melting and sections of thick ice at its poles. ‘equator due to freezing.
This was the same behavior predicted in the team models and supported by earlier data collected by Cassini.
“Experiencing ice rotation allows us to place restrictions on circulation patterns,” Lobo explains.
In addition, it also helps scientists understand which parts of the underground ocean could be as hospitable to life and which could one day inform efforts to look for signs of life, Thompson concluded.
These conclusions, entitled, “A pole-to-sea-belt crossing an orbit on Enceladus,” were published this week in Nature Geoscience.