Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellites see largest jet of particles created between Sun and Earth

13.01.2006


A flotilla of space-weather satellites – ESA’s Cluster and NASA’s ACE and Wind - observed for the first time steady large-scale jets of charged particles in the solar wind between the Sun and Earth.



When such huge jets of particles impact on Earth’s magnetic shield, they could cause powerful magnetic storms on our planet. Understanding the mechanism behind these phenomena - called ‘magnetic reconnection’ – is also fundamental to many explosive phenomena, such as solar flares, powerful gamma-ray bursts from ‘magnetars’ (dead stars noted for their extreme magnetic fields) and laboratory nuclear fusion.

Magnetic reconnection is a natural process by which the energy of magnetic field is converted into particle energy and by which, for instance, solar particles can penetrate through Earth’s magnetic shield, sometimes causing magnetic storms as well as beautiful ‘aurorae’, or polar lights.


Magnetic reconnection takes place when sheets of oppositely directed magnetic field get pressed together. In doing so, the sheets cross to form an X-shape that is then temporarily broken to form a new magnetic line geometry.

The creation of a different geometry induces jets of electrically charged particles and also allows solar material to pass through newly created ‘cracks’ in the previously impenetrable magnetic field configuration.

So far, magnetic reconnection events have been almost exclusively reported in Earth’s magnetosphere. This is the natural magnetic shield surrounding Earth. It is composed of magnetic field lines generated by our planet, and defends us from the continuous flow of charged particles that make up the solar wind by deflecting them away from Earth.

However, when the interplanetary magnetic field lines carried by the solar wind happen to be in the opposite orientation to Earth’s magnetic field lines, reconnection is triggered and solar material can break through Earth’s shield.

Previous reconnection events measured in Earth’s magnetosphere suggested that the phenomenon was intrinsically random and patchy in nature, extending not more than a few tens thousand kilometres.

However, a broader picture of magnetic reconnection emerged when six spacecraft – the four Cluster and the ACE and Wind satellites – were flying in the solar wind outside Earth’s magnetosphere, in sunward direction, on 2 February 2002.

During a time span of about two and a half hours, all spacecraft observed in sequence a single huge stream, or jet, of charged particles, up to 2.5 million kilometres (390 Earth radii) wide, caused by the largest reconnection event ever measured.

“If the observed reconnection were patchy, one or more spacecraft most likely would have not encountered an accelerated flow of particles,” says Tai Phan, from the University of California, Berkeley, USA, lead author of the results.

“Furthermore, patchy and random reconnection events would have resulted in different spacecraft detecting jets directed in different directions, which was not the case.”

The fact that the spacecraft detected the jet for more than two hours, also implies that the reconnection must have been almost steady over at least that timespan. Another 27 reconnection events of large magnitude – with the associated jets - were identified by ACE and Wind, four of which extended more than 100 Earth radii, or 650 000 kilometres.

Thanks to these additional data, scientists could conclude that reconnection in the solar wind is to be looked at as an extended and steady phenomenon.

Magnetic reconnection, responsible for transport of mass and energy across Earth’s magnetic defences, is a central issue in space physics. Consequences of this transport can be strong magnetic storms that have the potential to severely impair critical technology infrastructure.

Potential damage includes widespread power failures, pipeline corrosion, shutdown of cable systems, satellite failures, inaccurate GPS positioning and disturbed radio navigation.

Understanding magnetic reconnection is also fundamental when having to control magnetic fields and particles energy during nuclear experiments in laboratories. One of the keys to producing ‘clean’ nuclear energy (nuclear fusion) is making sure that reconnection phenomena do not take place, as they could cause powerful and dangerous jets of particles to be released uncontrolled.

“Only with co-ordinated measurements by spacecraft like Cluster, ACE and Wind can we probe the near-Earth space environment with unprecedented detail and in three dimensions,” continued Phan.

“This is the only natural laboratory were the physics of plasma and the magnetic phenomena that drive it can be studied in situ, paving the way to many applications,” he concluded.

Philippe Escoubet | alfa
Further information:
http://www.esa.int/esaSC/SEMAFQG23IE_index_0.html

More articles from Earth Sciences:

nachricht Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation

nachricht Citizen science campaign to aid disaster response
28.04.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>