December 17, 2008
Breach in Earth’s Magnetic Field Cause for Concern
Researchers announced on Thursday that current satellite surveillance has exposed the biggest breach ever seen in the magnetic field that shields the Earth from the majority of the sun's aggressive rays. The unearthing was found last summer by Themis, a group of five NASA satellites.
Scientists have known for a long time that the Earth's magnetic field, which protects us from harsh space weather, is comparable to an older home lets in brutal eruptions of charged particles from the sun. This kind of breach may cause luminous auroras and can disturb both satellite and ground communications.
Surveillance from Themis indicates that the Earth's magnetic field sometimes contracts cracks, letting solar wind break through the Earth's upper atmosphere.
Last summer, Themis mapped out a coating of solar particles to be 4,000 miles deep in the outermost area of the Earth's magnetosphere, the biggest rip of the defensive shield found thus far.
"It was growing rather fast," said Themis scientist Marit Oieroset of the University of California.
These kinds of breaches are momentary, and the one discovered last year was open for an hour, Oieroset added.
Solar flares are a likely hazard to astronauts in orbit but usually are not a danger to people on the Earth.
Scientists originally thought the broadest solar breach happened when the Earth's and sun's magnetic fields are faced in differing positions.
However, information from Themis established that the reverse was true. The solar wind passed into the Earth's protective shield twenty times greater than when the magnetic fields were united, Oieroset noted.
The Themis findings may affect how scientists forecast the exactness of solar storms and their consequence on power grids, airline and military communications and satellite signals.
Image Courtesy Of NASA
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