Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Frictional Heat Powers Hydrothermal Activity on Enceladus

23.11.2017

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that the moon has a porous core that allows water from the overlying ocean to seep in, where the tidal friction exerted on the rocks heats it. This shows a computer simulation based on observations from the European-American Cassini-Huygens mission.


Surface, ocean and core of Saturn's moon Enceladus. Computer simulation shows how the icy moon heats water in a porous rock core.

Source: Surface – NASA/JPL-Caltech/Space Science Institute; Core – Choblet et al (2017); Graphic composition – ESA

It also offers among others an answer to the long-standing question of where the energy that can support water in liquid form on the small, cryovulcanic moon far from the sun comes from. The Heidelberg University research group led by planetary scientist Assistant Professor Dr Frank Postberg participated in the investigation.

In 2015, the researchers had already shown that there must be hydrothermal activity on Saturn's moon. Icy volcanoes on Enceladus launch huge jets of gas and icy grains that contain fine particles of rock into space. A detector on the Cassini space probe was able to measure these particles. They originate on the seafloor more than 50,000 metres below the moon's ice shell, which ranges in thickness from three to 35 kilometres.

Using computer simulations and laboratory experiments, the scientists discovered signs that deep below the rock and the water interact – at temperatures of a least 90 degrees Celsius. But where does the energy for the hydrothermal systems that drive the transport of matter come from? And how exactly do the grains of rock get to the surface of the icy moon?

The current studies under the direction of the University of Nantes (France) offer an explanation. According to Dr Postberg, the rock core of Enceladus is probably porous, which is why the water from the overlying ocean is able to deeply permeate it. At the same time, strong tidal forces from Saturn affect the “loose” rock in the moon's core.

The new computer simulations show that the frictional heat is transferred very efficiently to the water circulating through the core, heating it to more than 90 degrees Celsius. This water dissolves some constituents of the rocky material. At certain hotspots, the hydrothermal fluids vent back into the ocean. Due to the cooling dissolved material now partially precipitates as fine particles, which are carried by the warm water to the ocean's surface. The hotspots are located primarily at the poles of Enceladus.

The ascending hydrothermal fluids probably trigger local melting in the ice layer of the polar region. According to Dr Postberg, this explains why the ice layer at the poles is considerably thinner than at the equator – three to ten kilometres versus 35 kilometres. “At the south pole, the water can even rise through fissures almost to the moon's surface.

There, the microscopically small grains of rock from the core are catapulted along with ice particles into space, where they were measured by the instruments on the Cassini space probe,” explained the Heidelberg planetary scientist. The study also showed that only this heat source in the core can keep the overlying ocean water from freezing. Without it, the ocean would completely freeze in less than 30 million years. Dr Postberg conducts research at the Klaus Tschira Laboratory for Cosmochemistry. The laboratory ist part of the Institute of Earth Sciences at Heidelberg University. It is funded by the Klaus Tschira Foundation.

The aim of the Cassini-Huygens mission, a joint project of NASA, ESA, and Italy's ASI space agency that began in 1997, was to gain new insights into the gas planet Saturn and its moons. The Cassini space probe began orbiting Saturn in 2004. The mission concluded in September of this year when the probe entered Saturn's atmosphere. The latest research results were published in the journal “Nature Astronomy”.

Original publication:
G. Choblet, G. Tobie, C. Sotin, M. Běhounková, O. Čadek, F. Postberg & O. Souček: Powering prolonged hydrothermal activity inside Enceladus. Nature Astronomy (published online 6 November 2017), doi: 10.1038/s41550-017-0289-8

Contact:
Assistant Professor Dr Frank Postberg
Institute of Earth Sciences
Klaus Tschira Laboratory for Cosmochemistry
Phone +49 6221 54-8209
frank.postberg@geow.uni-heidelberg.de

Communications and Marketing
Press Office
Phone +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Weitere Informationen:

http://www.geow.uni-heidelberg.de/researchgroups/postberg/

Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>