How space eruptions happen

The picture of a space eruption has been taken by the EIT instrument on the SOHO spacecraft. Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA

(PhysOrg.com) -- Mathematicians at the University of St Andrews have made a discovery which could lead to a better understanding of why huge eruptions occur in space.

The team has found new models of small structures in space plasmas, called "current sheets", which could help explain how explosions in the solar atmosphere happen.

Dr Thomas Neukirch, a Reader in Applied Mathematics at the School of Mathematics and Statistics explained the phenomenon.

He said, "Plasmas are gases or fluids that are able to conduct electric currents. While in our direct environment plasmas are rare (apart from technical applications such as neon lights or plasma TV screens), in space most matter is in the plasma state."

Solar scientists have shown that the enormous energies needed for eruptions come from the interaction of the plasma with magnetic fields.

Dr Neukirch continued, "One can imagine magnetic fields as a collection of elastic strings, and like elastic strings they can be stretched and twisted, thus storing energy. And just like elastic strings, magnetic fields can tear if overstretched and release the stored energy, thus leading to an eruption.

"A major difference between magnetic fields and elastic strings is that magnetic field lines cannot have loose ends as strings can. When magnetic fields tear apart every field line has to find a partner to which it reconnects. This process is therefore called magnetic reconnection."

According to the researchers, observations clearly show that magnetic reconnection is happening, for example, on the Sun, yet this has surprised experts as the usual conditions in most space plasmas should not allow it to happen.

Dr Neukirch said, "Scientists believe that the solution to this puzzle is that during the twisting and stretching of the magnetic field very small regions of plasma form which carry large electric currents - so-called current sheets.

"The conditions in these current sheets are much more favourable for magnetic reconnection to happen and therefore understanding current sheets is crucial for understanding how large eruptions can happen."

In the solar atmosphere and in many other space plasmas the electric currents should flow along the magnetic field, but in the most widely used current sheet model this is not the case.

The new models have extended the possibilities to understand the energy release process and may therefore lead to major advances in our understanding of magnetic reconnection in space plasmas.

Provided by University of St Andrews

   

• MrGrynch - Apr 07, 2009
  • Rank: 2.6 / 5 (5)
  Magnetic reconnection is a myth. Stars are fed externally via Birkeland Currents. You can't have a magnetic field without moving current. Remove the current and there is no more field. This basic fact has been ignored for decades. When these scientists stop talking about magnetic fields as if the currents that create them don't exist then they will see that what is seen as "magnetic reconnection" is actually another common attribute of plasmas.. the differentiation of dissimilar charge potentionals into what is called a double layer. These double layers act like a type of insulator and occasionally these fail under stress, violently releasing energy until new layers can be formed. This has been known about plasmas for decades.
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• mharratsc - Apr 07, 2009
  • Rank: 3 / 5 (4)
  Well you have to cut em a little slack- at least they're a step beyond most of the 'norm'... they understand that it is plasma energy causing the eruptions. Remember- most of them still think plasma is an electrically inert, heated gas :P
  
  However, as a taxpayer it does burn my arse that these clowns are getting my tax money to "discover" something that is already published in easy-to-read layman's terms right on the web... >.
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• dogma - May 01, 2009
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  As an amateur I can understand the previous comments and wonder what the F. These guys (in the article) get notice for something already known and understood? They should be unemployed!
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