Scientists have recently suggested that extraterrestrial life is more likely to exist on worlds with subterranean oceans like Enceladus. Today, scientists revealed that the oceans of Enceladus are strikingly similar to Earth’s Antarctic Ocean.
Global circulation processes may be operating within the ocean of Saturn’s moon Enceladus, transferring heat and various substances from the bottom to the overlying layers of water, from the poles to the equator. This is the conclusion reached by planetary scientists who have built a new model of the ocean based on data from the Cassini station and current knowledge of the Earth’s Antarctic Ocean.
What made Enceladus important to scientists?
Interest in Enceladus, Saturn’s 500 kilometer icy moon, arose after the Cassini interplanetary station found evidence for the existence of a global subglacial ocean at least 30 kilometers deep. This was indicated by fluctuations in the satellite’s position and plumes ejected from fissures near the South Pole.
In addition to water, carbon dioxide, ammonia and methanol, the emissions contained hydrogen and organic molecules, suggesting hydrothermal activity at the ocean floor. The satellite began to be considered one of the places where life can exist, in particular, archaea can live in such an ocean.
Enceladus’ oceans are similar to Earth’s Antarctic Ocean
A group of planetary scientists led by Ana Lobo of the California Institute of Technology has published the results of modeling the processes that may be taking place in the ocean of Enceladus. Scientists relied on Cassini data and modern ideas about the Earth’s high latitude oceans.
The fact is that the observed heterogeneity of the thickness of the satellite’s ice crust (at the poles it is thinner than near the equator), according to the researchers, is a convincing indicator that the local regions of freezing and melting at the boundary between the ocean and the crust change the density of the subsurface ocean due to heat exchange and fluxes of fresh and salt water.
Illustration of the interior of Enceladus and its subterranean oceans. Credit: NASA/JPL-Caltech
Similar processes take place on Earth in the Southern Ocean, where large-scale circulation processes depend on the interaction between water and glaciers. It is therefore possible to simulate the circulation processes that will take place in the ocean of Enceladus, depending on its different local characteristics.
Scientists have concluded that the global pole-to-equator circulation will work inside the ocean, which will affect the heat distribution (in this case, heat from hotspot areas can spread throughout the ocean). ocean) and the transport of various substances from the bottom to the overlying layers of water. Near the South Pole, the ocean will be divided into layers of different salinity and may have a freshwater lens.
If the ocean is assumed to have an average salinity equal to or greater than the salinity of its deepest layers, then the freshwater lens feeding the geysers will have a salinity of at least two grams per kilogram of water. lower than the average salinity of the entire ocean. which should be taken into account in future studies of the satellite.
Researchers hope that future missions to the icy satellites of giant planets, such as Dragonfly, Europa Clipper and JUICE, will reveal more about the oceans of Europa, Ganymede and Titan.
In particular, their research should make it possible to establish a link between the properties of the ocean at the boundary with the crust and the global circulation inside it. We will thus be able to better understand which satellites are most conducive to the development of microbiological life on them.