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 Predicting eruptions using satellites and math
28.06.2017 | Frontiers

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>