explanation
On May 10, for some unknown reason, the Solar Wind [ http://www-istp.gsfc.nasa.gov/Education/wsolwind.html ] virtually stopped. Normally our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] emits a wind [ http://antwrp.gsfc.nasa.gov/apod/ap970217.html ] of between five and ten energetic particles per cubic centimeter moving outward at about 500 kilometers per second. Late on May 10, however, this gale was reduced [ http://www-istp.gsfc.nasa.gov/istp/news/9912/prsample.html ] to a mere breeze of one particle per every five cubic centimeters. The Sun's Corona [ http://antwrp.gsfc.nasa.gov/apod/ap990915.html ] was suddenly able to flow out into the Solar System [ http://www.fourmilab.ch/solar/solar.html ] relatively unimpeded, creating beams of energetic electrons [ http://www.nmsi.ac.uk/on-line/electron/section2/discovery.html ]. One such beam apparently reached Earth's North Magnetic Pole [ http://antwrp.gsfc.nasa.gov/apod/ap991019.html ], and was seen as the unusual X-ray aurora digitally reconstructed in the above false-color image [ http://www-istp.gsfc.nasa.gov/istp/news/9912/immovies.html ]. Our atmosphere absorbed the electrons. This display gave direct evidence, however, that Earth's North Magnetic Pole [ http://www.geolab.nrcan.gc.ca/geomag/e_nmpole.html ] was connected to the Sun, while the Earth's South Magnetic Pole connected [ http://sunearth.gsfc.nasa.gov/sechtml/tut.html ] to the distant Solar System. The Solar Wind [ http://antwrp.gsfc.nasa.gov/apod/ap990208.html ] returned to normal on May 12.
Explanation
false