Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cassini Finds an Atmosphere on Saturn’s Moon Enceladus


The Cassini spacecraft’s two flybys of the icy moon Enceladus have revealed that the moon has a significant atmosphere. Scientists using Cassini’s magnetometer instrument for their studies, say the source may be due to volcanism, geysers, or gases escaping from the surface or its interior.

When the Cassini had its first encounter with Enceladus on 17th February 2005 at an altitude of 1,167 kilometres (725 miles), the magnetometer instrument saw a striking signature in the magnetic field. On 9th March 2005 Cassini approached to within 500 km (310 miles) of Enceladus’ surface and obtained additional evidence.

The observations showed a bending of the magnetic field with the magnetospheric plasma being slowed and deflected by the moon. In addition magnetic field oscillations were observed. These are caused when electrically charged (or ionised) molecules interact with the magnetic field by spiralling around the field line. This interaction creates characteristic oscillations in the magnetic field at frequencies that can be used to identify the molecule. The observations from the Enceladus flybys are believed to be due to ionised water vapour.

"It was a complete surprise to find these signals at Enceladus. These new results from Cassini may be the first evidence of gases originating either from the surface or possibly from the interior of Enceladus," said Professor Michele Dougherty, of Imperial College, London and Principal Investigator for the Cassini magnetometer. In 1981 the Voyager spacecraft flew by Enceladus at a distance of 90,000 kilometres (56,000 miles) without detecting an atmosphere. It is possible that detection was beyond Voyager’s capabilities or something may have changed since that flyby.

This is the first time since Cassini arrived in orbit around Saturn last summer that an atmosphere has been detected around a moon of Saturn, other than its largest moon, Titan. Enceladus is a relatively small moon. The amount of gravity it exerts is not enough to hold an atmosphere very long. Therefore at Enceladus, a strong continuous source is required to maintain the atmosphere.

The need for such a strong source leads scientists to consider eruptions from the surface, such as volcanoes and geysers. If such eruptions are present, Enceladus would join two other such active moons, Io at Jupiter and Triton at Neptune. “Enceladus could be Saturn’s more benign counterpart to Jupiter’s dramatic Io”, said Professor Fritz Neubauer, co-investigator for the Cassini magnetometer from the University of Cologne, Germany.

Since the Voyager flyby scientists have suspected that this moon is geologically active and is the source of Saturn’s icy E ring. Enceladus is the most reflective object in the solar system, reflecting about 90 percent of the sunlight that hits it. If Enceladus does have ice volcanoes, the high reflectivity of the moon’s surface might result from continuous deposition of icy particles originating from the volcanoes.

Enceladus’ diameter is about 500 kilometres or 310 miles (the equivalent distance between London and Penzance). Yet despite its small size Enceladus exhibits one of the most interesting surfaces of all the icy satellites.

Gill Ormrod | alfa
Further information:

More articles from Physics and Astronomy:

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>