NASA: A Giant Breach in Earth's Magnetic Field

http://science.nasa.gov/headlines/y2008/16dec_giantbreach.htm?list1049613

On June 3, 2007 NASA's five THEMIS spacecraft discovered a breach in Earth's magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms. But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.