Hole found in magnetic field

2008-12-17 09:44

Los Angeles - Recent satellite observations have revealed the largest breach yet seen in the magnetic field that protects Earth from most of the sun's violent blasts, researchers reported on Tuesday.

The discovery was made last summer by Themis, a fleet of five small Nasa satellites.


Observations from Themis show the Earth's magnetic field occasionally develops two cracks, allowing solar wind - a stream of charged particles spewing from the sun at 1.6 million kph - to penetrate the Earth's upper atmosphere.

Last summer, Themis calculated a layer of solar particles to be at least 6 400km thick in the outermost part of the Earth's magnetosphere, the largest tear of the protective shield found so far.




The research was funded by Nasa and the National Science Foundation.


The Themis results could have bearing on how scientists predict the severity of solar storms and their effects on power grids, airline and military communications and satellite signals.
