Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Chicago instrument detects particles near Saturn’s moon Enceladus

27.04.2005


Debris could be dust cloud around the moon


Saturn’s moon Enceladus. Image credit: NASA/JPL/Space Science Institute.



An instrument designed and built at the University of Chicago for the Cassini space probe has discovered dust particles around Enceladus, an ice-covered moon of Saturn that has the distinction of being the most reflective object in the solar system. The particles could indicate the existence of a dust cloud around Enceladus, or they may have originated from Saturn’s largest ring, the E-ring.

"We are operating on the plane of the E-ring, and things are very complicated there," said Thanasis Economou, a Senior Scientist at the University of Chicago’s Enrico Fermi Institute. "It will take a few more flybys to distinguish the dust flux originating from the E-ring as opposed to one around Enceladus."


The discovery is the first for the Chicago instrument, called the High Rate Detector. "During all this time from Earth to Saturn, we didn’t have any real test of the instrument. I was very happy to see that the instrument performs well after so many years," Economou said.

The National Aeronautics and Space Administration launched Cassini, an international mission involving 17 nations, in October 1997. Last July, after a journey of 2.2 billion miles, Cassini became the first spacecraft to orbit Saturn.

Cassini scientists regard Enceladus as an increasingly interesting target. So much so that mission planners are revising the altitude of the next flyby to get a closer look. Additional Cassini encounters with Enceladus are scheduled for July 14, 2005, and March 12, 2008. The July 14 flyby was to be at an altitude of 620 miles, but the mission team now plans to lower that altitude to 109 miles. This will be Cassini’s lowest-altitude flyby of any object in the scheduled four-year tour.

Cassini encountered Enceladus at an altitude of 733 miles on Feb. 17. On that date, the Chicago instrument recorded thousands of particle hits during a period of 37 and a half minutes. Cassini executed another flyby of Enceladus on March 9 at an altitude of 311 miles. "Again we observed a high stream of dust particles," Economou said.

The largest particles detected by the Chicago instrument measure no more than the diameter of a human hair-too small to pose any danger to Cassini. "Our measurements are important to evaluate any risk to the spacecraft," Economou said.

The HRD is part of a larger instrument, the Cosmic Dust Analyzer, which with further analysis may be able to determine whether the particles are made of ice or dust. Enceladus measures 310 miles in diameter and reflects nearly 100 percent of the light that hits its ice-covered surface.

"If you look at the surface on Enceladus, it’s very smooth," Economou said, and varies little in altitude. Scientists have speculated that Enceladus is the source of Saturn’s E-ring, the planet’s widest, stretching 188,000 miles. It is possible, the scientists say, that gravitational interactions between Enceladus and another moon of Saturn have triggered some form of water volcanism.

"The High Rate Detector measurements are extremely important in order to understand the role of Enceladus as the source of the water ice particles in the E-ring," said Ralf Srama of Germany’s Max Planck Institute for Nuclear Physics, who heads the Cosmic Dust Analyzer science team. This study requires precise measurements of dust density in the Enceladus region, "but without the High Rate Detector this would not be possible," Srama said.

Enceladus orbits Saturn at a distance of approximately 147,500 miles, almost two-thirds the distance from Earth to the moon. Only one of Saturn’s 31 known moons is closer to the planet.

The HRD was created by Anthony Tuzzolino, Senior Scientist in the Enrico Fermi Institute, under the direction of the late John Simpson, the Arthur Holly Compton Distinguished Service Professor Emeritus in Physics. The HRD was designed to collect data on Saturn’s rings and is capable of counting up to 100,000 impacts per second.

Cassini carries a total of 12 primary instruments that often must compete with one another so that the orbiter is properly oriented for collecting their data. "We did our best in order to make this happen, and the preparations and negotiations for these encounters were enormous," Srama said. "These were perfect flybys, and we did everything possible."

Steve Koppes | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Physics and Astronomy:

nachricht From the cosmos to fusion plasmas, PPPL presents findings at global APS gathering
13.11.2018 | DOE/Princeton Plasma Physics Laboratory

nachricht A two-atom quantum duet
12.11.2018 | Institute for Basic Science

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: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>