Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Saturn's skewed ring current

23.08.2007
Images taken by Cassini’s Magnetospheric Imaging Instrument (MIMI) show that Saturn’s ring current is a warped disc that balloons out of the equatorial plane on the planet’s dayside and remains a thin disk that rises above the plane at larger distances on the nightside.

Dr Stamatios “Tom” Krimigis, the Principal Investigator for the instrument, who is presenting images at the European Planetary Science Congress in Potsdam on Thursday 23rd August, said, “Ring currents surround planets sort of like the brim of a hat. Uniquely in Saturn’s case, that brim has been crushed at the front and tipped up at the back, so it’s pretty bent out of shape!”


MIMI image showing the energetic neutral atom emission from Saturn’s ring current as the energetic ions charge exchange with the dense water products neutral cloud surrounding Saturn. The pronounced asymmetry (bright emission in the upper left quadrant, located between noon and dawn) rotates with the planet, and the bright spot will appear 180° away approximately 5..5 hours later.

The presence of a ring current around Saturn was first suggested in the early 1980s following magnetic anomalies observed by the Pioneer 11 and Voyager 1 and 2 spacecraft. Ring currents are also found around Earth and Jupiter. They are caused when plasma becomes trapped between mirror points on magnetic field lines, similar to the Van Allen radiation belts surrounding Earth, and gradually drifts around the planet. The aggregate motion of all of the hot ions distributed around the equator generates an electric current. On Saturn, the source of the plasma is material from the rings and gas vented by geysers on the moon Enceladus, which is subsequently ionized and accelerated. The MIMI images show that the ring current occupies a region of the equatorial plane between 540 000 kilometres and 1 080 000 kilometres from the centre of Saturn. They also show that Saturn’s ring current is persistently asymmetric (unlike Earth’s), and that the asymmetry rotates nearly rigidly with Saturn.

MIMI, which was developed by an international team led by the Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Maryland, has three distinct sensors that allow it to “visualize the invisible” and show the plasma and radiation belts in Saturn’s environment in an image. The MIMI instrument includes an Ion and Neutral Camera developed by APL, a spectrometer built by the University of Maryland, and a low energy particle detector developed by the Max-Planck-Institut fuer Sonnensystemforschung and a number of co-investigator institutions including CESR in Toulouse.

Anita Heward | alfa
Further information:
http://www.europlanet-eu.org/index.php?option=com_content&task=view&id=107&Itemid=32

More articles from Physics and Astronomy:

nachricht MSU astronomers discovered supermassive black hole in an ultracompact dwarf galaxy
14.08.2018 | Lomonosov Moscow State University

nachricht ASU astrophysicist helps discover that ultrahot planets have starlike atmospheres
13.08.2018 | Arizona State University

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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>