Solar flares: Wonder what effect they have on us?
- Friday, September 16, 2005
ANCHORAGE, Alaska - A huge sunspot has been blasting Earth with
magnetic clouds for weeks, producing some of the most vibrant and
visible summertime auroras in years, according to NASA scientists.
Scientists said the magnetic flare-ups from Sunspot 798 may last
through the weekend.
"It is a fairly large geomagnetic storm that we've had over the past
24 hours, and it should continue a little while longer," said aurora
researcher Dirk Lummerzheim, at the Geophysical Institute at the
University of Alaska Fairbanks.
Skywide northern lights have awed Alaskans since last week and
produced red displays as far south as Arizona. However, current
forecast maps predict the auroras will not be visible south of
A North Pole photographer who signed e-mail messages as "Santa" posted
a dazzling picture of a display on Thursday on the Geophysical
Institute's online aurora forum.
The shimmering green light came courtesy of Sunspot 798, which sent a
gusting magnetic cloud hurtling toward Earth at more than a million
miles per hour.
Sunspots are planet-sized splotches formed by the sun's roiling
magnetic field. The sunspots become unstable and explode, producing
flares and propelling charged particles and radiation into space.
Sunspot activity can produce a geomagnetic storm that makes regular
daily auroral activity much more visible than usual.
Solar scientists say the sun is supposed to be in the quiet phase of
its 11-year cycle, with sunspot activity close to minimum.
But the year has so far produced four severe geomagnetic storms and 15
"The sunspots of 2005, while fewer, have done more than their share of
exploding," said solar physicist David Hathaway, of the National Space
Science and Technology Center in Huntsville, Ala.
On the Net:
Geophysical Institute: http://www.gi.alaska.edu/