Those pesky Mayans and their calendar.
Scientists find hole in Earth's magnetic field
Largest breach yet in the field that protects planet from sun's violent blastsScientists initially believed the greatest solar breach occurs when the Earth's and sun's magnetic fields are pointed in opposite directions. But data from Themis found the opposite to be true. Twenty times more solar wind passed into the Earth's protective shield when the magnetic fields were aligned, Oieroset said.
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.
Earlier this year, the National Oceanic and Atmospheric Administration reported that the first sunspot of a new 11-year cycle has appeared in the sun's northern hemisphere.
Jimmy Raeder, a physicist with the University of New Hampshire, predicted a more intense solar cycle. That's because the Earth's and the sun's magnetic fields will be in sync at the cycle's peak, expected in 2012, that will cause an influx of solar particles, Raeder said.
http://www.msnbc.msn.com/id/28269124/ More on the StoryThe new observations "overturn the way that we understand how the sun's magnetic field interacts with the Earth's magnetic field," said David Sibeck of NASA's Goddard Space Flight Center in Greenbelt, Md., during a press conference today at the annual meeting of the American Geophysical Union in San Francisco.
The bottom line: When the next peak of solar activity comes, in about 4 years, electrical systems on Earth and satellites in space may be more vulnerable.
How it works
Earth's magnetic field carves out a cavity in the sun's onrushing field. The Earth's magnetosphere is thus "buffeted like a wind sock in gale force winds, fluttering back and forth in the" solar wind, Sibeck explained.
Both the sun's magnetic field and the Earth's magnetic field can be oriented northward or southward (Earth's magnetic field is often described as a giant bar magnet in space). The sun's magnetic field shifts its orientation frequently, sometimes becoming aligned with the Earth, sometime becoming anti-aligned.
Scientists had thought that more solar particles entered Earth's magnetosphere when the sun's field was oriented southward (anti-aligned to the Earth's), but the opposite turned out to be the case, the new research shows.
Essentially, the Earth's magnetic shield is at its strongest when scientists had thought it would be at its weakest.
When the fields aren't aligned, "the shield is up and very few particles come in," said physicist Jimmy Raeder of the University of New Hampshire in Durham.
The Sun operates on an 11-year cycle, alternating between active and quiet periods. We are currently in a quiet period, with few sunspots on the sun's surface and fewer solar flares, though the next cycle of activity has begun. It is expected to peak around 2012, bringing lots of sunspots, flares and coronal mass ejections (CMEs). CMEs can interact with the Earth's magnetosphere, causing problems for satellites, communications, and power grids.
This upcoming active period now looks like it will be more intense than the previous one, which peaked around 2006, some scientists think. The reason is the changes in the sun's alignment.
http://news.yahoo.com/s/space/20081216/sc_space/leaksfoundinearthsprotectivemagneticfield
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