Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Violent truth behind Sun’s ‘Gentle Giants’ uncovered

10.02.2003


Solar Physicists at the Mullard Space Science Laboratory, University College London (MSSL-UCL) have discovered new clues to understanding explosions on the Sun.



Coronal mass ejections are violent explosions that can fling electrified gas [plasma] with a mass greater than Mount Everest towards the Earth with destructive consequences for satellites. They can originate from active regions on the Sun, long known to consist of forests of loops filled with plasma. These active loops are roughly 50,000 km in size. However, active regions on either side of the solar disk are frequently connected by giant loops, which can bridge the Sun’s equator. These loops have long been thought of as the gentle giants of the Sun, but in a paper to be published early this year in the journal of Astronomy and Astrophysics, the researchers describe the explosive characteristics of these giants.

An example of a giant loop can clearly be seen in figure one, where the width of the arrow represents the size of the Earth. These giant loops of plasma are 450,000 km long - large enough to engulf 40 Earths. If Concorde could fly along one of these loops, it would take nearly 9 days to complete the journey!


Coronal mass ejections are violent explosions that cause all sorts of effects from the destruction of satellites, to the creation of the aurora. These effects are commonly referred to as ’space weather’. Using data taken by the Yohkoh and SOHO satellites studying the Sun, the scientists analysed the giant loops to see how frequently they erupt. In the past only one eruption had been observed and so they have been considered the gentle giants of the Sun that do not explode. The researchers found that not only can these huge structures be thrown away from the Sun, but they can also be heated up by a factor of 5, to temperatures of 14 thousand times the temperature of boiling water. They investigated how the loops explode, and it was found that the longer the loop, the more likely it is to erupt - so these are culprits to watch more carefully in the future!

Alexi Glover, part of the space weather team at the European Space Agency [ESA], explains, "These huge loops have been observed for many years - but their connection with coronal mass ejections is only just being understood. In the future we hope to be able to predict coronal mass ejections before they take place, and step by step we are heading towards that goal."

Because of our increasing reliance on communication and navigation satellites for TV, GPS and national and international security, it is vital that we understand how the Sun can release these explosions.

Dr. Louise Harra of MSSL-UCL says, "Space weather is a rapidly developing field, and a vital key to progress is by understanding in detail the physics of Sun. The UK plays a leading role in solar physics and these new results are helping us make substantial advancements in our understanding of these beautiful, but potentially hazardous, coronal mass ejections."

Julia Maddock | alfa
Further information:
http://www.pparc.ac.uk/Nw/Press/giant_loops.asp

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: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>