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This image, provided by Dr. Bernard Jackson at UCLA, shows the solar wind within the earth's orbit (ellipse) and coming out in a series of spokes (sectors) from the sun. The blue dot is the Earth. The spokes converge on the Sun. Note, the Earth is about to cross one of the solar wind sectors. This often triggers magnetic storms and weak aurora. |
Open magnetic field lines from the Sun's surface act as magnetic pipes down which the heated plasma from the solar corona and inner corona may escape if heated enough...usually by flares. But there is also a constant wind emitted by the Sun due to the expansion of the solar corona. The dynamics are rather complex and only partially understood. For more information, visit the Solar Wind information page at the NASA Marshall Space Flight Center. The NASA SOHO satellite regularly monitors the solar surface for coronal mass ejections and their LASCO instrument has made some Great Movies!. Astronomers have even found a way to image the solar wind to create real 3-D images of it. See Dr. Bernard Jackson's SMEI Program at UCLA for some great images and movies! NASA's ACE satellite provides minute-to-minuts measurements of the solar winds density and speed from a point 1 million miles from the Earth. This data is used in space weather forecasting.
Copyright 1997 Dr. Sten Odenwald
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