Sunspot Grows to 20 Times Size of Earth
2004 07 23
By By Robert Roy Britt
A sunspot group aimed squarely at Earth has grown to 20 times the size of our planet and has the potential to unleash a major solar storm.
The amorphous mix of spots, together called Number 652, has been rotating across the Sun and growing for several days. On Friday, it sat at the center of the solar disk.
Sunspots are areas of intense magnetic energy, cooler and darker than the surrounding surface of the thermonuclear furnace. Sometimes the magnetic fields let loose and huge amounts of radiation and charged particles are hurled into space.
The Sun's last bout of intense storminess occurred last fall, when a string of 10 major flares over two weeks knocked out satellites, damaged others, and forced the FAA to reroute airlines away from exposed polar routes.
No one can say if this sunspot group will let loose with a major storm, but it has the characteristics of a potentially big event.
"The implications of this spot have scientists on the edge of their seats," NASA said in a statement Friday. "If the active region generates coronal mass ejections (CMEs), massive explosions with a potential force of a billion megaton bombs, it will be a fairly direct hit to Earth and its satellites and power grids."
The Sun is now in a generally quiet period of a well-known 11-year cycle of activity. But sunspots and flares can occur at any time. Scientists do not fully understand why the spots appear or how they erupt.
The sunspot is clearly visible from Earth without a telescope. But don't look at the Sun without a proper, safe filter or other viewing technique, or permanent eye damage can result.
Article From: http://www.space.com/scienceastronomy/hugesunspots_040723.html