Cluster takes first look at acceleration processes driving aurora
Last Updated on Tuesday, 13 April 2010 19:24
Published on Tuesday, 13 April 2010 19:21
Using the Cluster spacecraft, scientists from University College London (UCL) have made the first direct observations of charged particles that lead to some of the brightest aurora. Dr Colin Forsyth will present the results at the RAS National Astronomy Meeting (NAM2010) in Glasgow on Monday 12th April.
The aurora, or northern and southern lights, are caused by highly energetic charged particles, normally held in space by Earth’s magnetic field, colliding with Earth’s upper atmosphere. As these high-energy particles collide with molecules in the atmosphere they lose energy, causing the atmospheric molecules to glow and heating the atmosphere. The result of is spectacular displays of shimmering curtains of red, green and blue light normally seen above the polar regions, but occasionally seen as far south as northern England.
Despite their frequent occurrence, there are still many questions regarding the physical processes behind the aurora. The particles that excite the aurora are accelerated up to high energies in a region extending to around 50 000 km (31 000 miles) above the atmosphere. By understanding the accelerating processes in this region, scientists hope to further understand the aurora.
Launched in 2000, the joint European Space Agency (ESA) and NASA Cluster mission consists of four identical spacecraft flying in a close formation around the Earth. Each spacecraft carries a suite of instruments to study the charged particles and electromagnetic fields in the space environment around the Earth known as the magnetosphere. The multi-point perspective of the Cluster spacecraft allows scientists build up a 3D picture of the magnetosphere.
Dr. Colin Forsyth has been leading an international team hoping to directly measure the acceleration of charged particles above the aurora. At NAM2010, Dr. Forsyth will present data from the Plasma Electron And Currents Experiment (PEACE), built by UCL’s Mullard Space Science Laboratory, showing this acceleration in action.
“The Cluster spacecraft have been manoeuvred such that one of them was at a higher altitude than the others when they passed over the auroral regions” said Dr. Forsyth. “We were then able to simultaneously measure the particle energies at different heights and thus their acceleration. These exciting new results will give us new insight into the accelerating processes and the transfer of energy from the magnetosphere into the atmosphere”.
These new observations are the first step in understanding the processes behind the aurora and its impact on the atmosphere. Dr. Forsyth and his team aim to link these and similar observations to observations of large-scale processes in the magnetosphere and detected on the ground in the auroral regions. This could be a key factor in understanding how energy from the magnetosphere affects Earth’s atmosphere.
Dr. Colin Forsyth
Mullard Space Science Laboratory
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NAM 2010 Press Office (12th – 16th April only)
University of Glasgow.
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Dr Robert Massey
Press and Policy Officer
Royal Astronomical Society
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Royal Astronomical Society
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Image of the auroral oval taken by the IMAGE spacecraft in ultraviolet. Credit: IMAGE-FUV team/NASA
Thanks to the IMAGE-FUV team for use of this image.
Schematic diagram of showing how Cluster made the observations
This study has been carried out by UCL Mullard Space Science Laboratory, Université de Toulouse and Centre National de la Recherche Scientifique (CNRS) in France, and Technische Universität Braunschweig in Germany.
MSSL is the UK's largest university-based space science research group and delivers a cutting-edge science programme, underpinned by a capability in space science instrumentation, systems engineering and project management. Website: www.mssl.ucl.ac.uk
NOTES FOR EDITORS
RAS NATIONAL ASTRONOMY MEETING 2010
The RAS National Astronomy Meeting 2010 will take place from 12-16th April at the University of Glasgow. The conference is held in conjunction with the UK Solar Physics (UKSP) and Magnetosphere Ionosphere and Solar-Terrestrial Physics (MIST) meetings. NAM2010 (www.astro.gla.ac.uk/nam2010/) is principally sponsored by the Royal Astronomical Society (RAS) and the University of Glasgow.
THE ROYAL ASTRONOMICAL SOCIETY
The Royal Astronomical Society (RAS: www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
THE UNIVERSITY OF GLASGOW
The University of Glasgow (founded 1451) is one of the world’s top 100 research universities with more than 70 per cent of its research rated as world-leading or internationally excellent. The Physics and Astronomy Department is one of the top four in the UK’s major research-intensive universities, the Russell Group.
The conference comes to Glasgow during the 250th anniversary year of the founding of the Regius Chair of Astronomy at the University of Glasgow, first held by astronomer and meteorologist Alexander Wilson in 1760. The present incumbent is Prof. John Brown, 10th Astronomer Royal for Scotland.