Scientists have learned the conditions at the bottom of the icy ocean of Enceladus, the satellite of Saturn
Enceladus - the sixth largest satellite of Saturn, is known for the active activity of geysers. Thanks to the Cassini spacecraft, many unique discoveries have been made, mostly about the nature of the ice geysers discovered, emitting water vapor and dust particles to a height of hundreds of kilometers. It was concluded that the leading role of Enceladus in the formation of one of the rings of Saturn. Last year, the results of research on the subsurface ocean existing on Enceladus were published. And finally, this week, two papers were published indicating the first clear signs of hydrothermal activity at the bottom of the subsurface ocean.
The scheme depicts the possible hydrothermal activity on and under the bottom of the subsurface ocean.
The first work concerns the microscopic particles of rock found by Cassini in the Saturn system.
A large study, which lasted 4 years, analyzed data from the spacecraft, the results of computer simulations and laboratory experiments, and led the researchers to conclude that tiny particles most likely formed when hot water containing dissolved minerals of Enceladus rock was released into the ocean, and interacts with cooler water. The temperatures required for interaction forming tiny rock particles are at least 90 degrees Celsius.
The cosmic dust analyzer, mounted on Cassini, recorded silica particles, the largest of which were 6-9 nanometers in size. A necessary condition for the formation of such particles is a large drop in the temperature of weakly alkaline and saline water, supersaturated with silica. A team of researchers from the University of Tokyo suggest that the necessary conditions exist at the bottom of the subsurface ocean when hot water comes out of the rocks and interacts with cold ocean water.
The small size of the particles suggests that they relatively quickly reach the surface of the ocean and outer space (a distance of 50 kilometers) - within a few months or years, otherwise their sizes would be larger.
The authors of the paper note that Cassini’s gravitational measurements suggest that Enceladus’s stone core is relatively porous, which allows water to seep from the ocean. Which gives a huge surface area where water and rocks can interact.
Scientists consider two hypotheses of methane in geysers
The second study suggests hydrothermal activity as one of two possible sources of methane in geysers, which erupt from the southern polar region of Enceladus. This conclusion was drawn from the results of extensive modeling of French and American scientists to address the issue of the unusual abundance of methane in geyser emissions. Research by a group of scientists clathrates in the ocean of Enceladus led them to the idea that methane is actively being produced by hydrothermal processes.
The scheme depicts the possible hydrothermal activity on and under the bottom of the subsurface ocean.
The first work concerns the microscopic particles of rock found by Cassini in the Saturn system.
A large study, which lasted 4 years, analyzed data from the spacecraft, the results of computer simulations and laboratory experiments, and led the researchers to conclude that tiny particles most likely formed when hot water containing dissolved minerals of Enceladus rock was released into the ocean, and interacts with cooler water. The temperatures required for interaction forming tiny rock particles are at least 90 degrees Celsius.
The cosmic dust analyzer, mounted on Cassini, recorded silica particles, the largest of which were 6-9 nanometers in size. A necessary condition for the formation of such particles is a large drop in the temperature of weakly alkaline and saline water, supersaturated with silica. A team of researchers from the University of Tokyo suggest that the necessary conditions exist at the bottom of the subsurface ocean when hot water comes out of the rocks and interacts with cold ocean water.
The small size of the particles suggests that they relatively quickly reach the surface of the ocean and outer space (a distance of 50 kilometers) - within a few months or years, otherwise their sizes would be larger.
The authors of the paper note that Cassini’s gravitational measurements suggest that Enceladus’s stone core is relatively porous, which allows water to seep from the ocean. Which gives a huge surface area where water and rocks can interact.
Scientists consider two hypotheses of methane in geysers
The second study suggests hydrothermal activity as one of two possible sources of methane in geysers, which erupt from the southern polar region of Enceladus. This conclusion was drawn from the results of extensive modeling of French and American scientists to address the issue of the unusual abundance of methane in geyser emissions. Research by a group of scientists clathrates in the ocean of Enceladus led them to the idea that methane is actively being produced by hydrothermal processes.
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Source: https://habr.com/ru/post/377263/
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