Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Theory Sheds Light On Space Enigma

25.02.2008
UK and German scientists explain intriguing phenomenon on Saturn’s moon
An enormous plume of dust and water spurts violently into space from the south pole of Enceladus, Saturn's sixth-largest moon. This raging eruption has intrigued scientists ever since the Cassini spacecraft provided dramatic images of the phenomenon.

Now, physicist Nikolai Brilliantov, at the University of Leicester, and colleagues in Germany, have revealed why the dust particles in the plume emerge more slowly than the water vapour escaping from the moon's icy crust.

Enceladus orbits in Saturn's outermost "E" ring. It is one of only three outer solar system bodies that produce active eruptions of dust and water vapour. Moreover, aside from the Earth, Mars, and Jupiter's moon Europa, it is one of the only places in the solar system for which astronomers have direct evidence of the presence of water.

The erupting plume on Enceladus is ejected by geyser-like volcanic eruptions from deep, "tiger-stripe" cracks within the moon's south pole. Some astronomers have suggested that the myriad tiny grains of dust from these eruptions could be the actual source of Saturn's E-ring. However, the dynamics and the origin of the plume itself have remained a mystery.

Now, Brilliantov, who is also on the faculty at the University of Potsdam, Germany and Moscow State University, working with Juergen Schmidt and Frank Spahn of Potsdam and Sascha Kempf of the Max Planck Institute for Nuclear Physics in Heidelberg, and the Technical University of Braunschweig, Germany have developed a new theory to explain the formation of these dust particles and to explain why they are ejected into space.

The researchers point out that once ejected the dust particles, which are in fact icy grains, and water vapour are too dilute to interact with each other and so the water vapour cannot be the cause of the dusty slowdown. Instead, the team suggests that the shift in speed must occur below the moon's surface before ejection.

The numerous cracks through which the plume material escapes from the moon's icy surface, and which can be hundreds of metres deep, are narrower at some points along their length. At these points temperature and pressure of vapour drop drastically down, causing condensation of vapour into icy grains and hence to formation of the dust-vapour mixture. The required vapour density to accelerate the grains to the observed speeds implies temperatures where liquid water can exist in equilibrium with solid ice and water vapour within the moon's frozen crust.

These peculiar conditions allow the water vapour to erupt rapidly carrying with it the dust particles. However, these particles undergo countless frequent collisions with the inside of the channel walls which causes friction that slows them down before final ejection. The larger the particle the slower the ejection speed. This effect, quantified by the new theory, explains the structure of the plume and eventually the particle size distribution of the E-ring of Saturn.

The existence of liquid water is a prerequisite for life and, while not suggesting there is life on Enceladus, offers another extraterrestrial place that might be searched.

The scientists published details of their findings in the journal Nature.

For More information, please contact Nikolai Brilliantov on 0116 252 2521
Email: nb144@le.ac.uk


The paper appeared in:

Nature, Vol 451, p. 685-688, |7 February 2008|doi:10.1038/nature06491

UNIVERSITY OF LEICESTER
- A member of the 1994 Group of universities that share a commitment to research excellence, high quality teaching and an outstanding student experience.

Ranked top for student satisfaction in England (jointly with Oxford) among mainstream universities (average score of 4.4 out of 5 for overall satisfaction)

Ranked as a Top 20 university by The Sunday Times University Guide, The Guardian University Guide and the UK Good University Guide

One of just 23 UK universities to feature in world’s top 200- Shanghai Jiao Tong International Index, 2005-07.

Ranked in top 200 world universities by the THES (Times Higher Education Supplement)

Short listed University of the Year in 2007 by The Sunday Times and Short listed Higher Education Institution of the Year - THES awards 2005 and 2006

Ranked top 10 in England for research impact by The Guardian

Students’ Union of the Year award 2005, short listed 2006 and 2007

Founded in 1921, the University of Leicester has 19,000 students from 136 countries. Teaching in 18 subject areas has been graded Excellent by the Quality Assurance Agency- including 14 successive scores - a consistent run of success matched by just one other UK University. Leicester is world renowned for the invention of DNA Fingerprinting by Professor Sir Alec Jeffreys and houses Europe's biggest academic Space Research Centre. 90% of staff are actively engaged in high quality research and 13 subject areas have been awarded the highest rating of 5* and 5 for research quality, demonstrating excellence at an international level. The University's research grant income places it among the top 20 UK research universities. The University employs over 3,000 people, has an annual turnover of £184m, covers an estate of 94 hectares and is engaged in a £300m investment programme- among the biggest of any UK university.

Ather Mirza | University of Leicester
Further information:
http://www.stock-space-images.com
http://www.le.ac.uk/press/experts/intro.html

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>