By SETH BORENSTEIN
AP Science Writer
WASHINGTON (AP) - Our
high-tech world seems to have easily weathered a solar storm that didn't
quite live up to its advance billing.
While some experts think
the threat from the solar storm passed by Thursday afternoon, space
weather forecasters said it's still too early to relax. That's because
there's a chance the storm's effects could continue and even intensify
through Friday morning.
And while this solar storm
may have fizzled, others may be lining up in the cosmic shooting gallery
in the coming, days month and year, the scientists agree.
"It looks to me like it's
over," NASA solar physicist David Hathaway said late Thursday afternoon,
after noticing a drop in a key magnetic reading.
That conclusion is
premature, said Doug Biesecker, a space scientist at the National
Oceanic and Atmospheric Administration's Space Weather Prediction Center
in Boulder, Colo., which forecasts solar storms. He pointed to an
increase in a different magnetic field measurement.
The storm, which started
with a solar flare Tuesday evening, caused a stir Wednesday because
forecasts were for a strong storm with the potential to knock electrical
grids offline, mess with GPS and harm satellites. It even forced
airlines to reroute a few flights on Thursday.
It was never seen as a
threat to people, just technology, and teased skywatchers with the
prospect of colorful Northern Lights dipping further south.
But when the storm finally
arrived around 6 a.m. EST Thursday, after traveling at 2.7 million mph,
it was more a magnetic breeze than a gale. The power stayed on. So did
GPS and satellites. And the promise of auroras seemed to be more of a
mirage.
"I think we just lucked
out," Jeffrey Hughes, director of the Center for Integrated Space
Weather Modeling at Boston University, said Thursday afternoon. "It just
didn't pack as strong a magnetic field as we were anticipating."
Scientists initially
figured the storm would be the worst since 2006, but now seems only as
bad as ones a few months ago, said Joe Kunches, a scientist at the NOAA
center. The strongest storm in recorded history was probably in 1859, he
said.
"It's not a terribly strong event. It's a very interesting event," Kunches said.
Forecasters can predict the
speed a solar storm travels and its strength, but the north-south
orientation is the wild card. This time it was a northern orientation,
which is "pretty benign," Kunches said. Southern would have caused the
most damaging technological disruption and biggest auroras.
North American utilities
didn't report any problems, said Kimberly Mielcarek, spokeswoman for the
North American Electric Reliability Corporation, a consortium of
electricity grid operators.
Astronomers say the sun has
been relatively quiet for some time. And this storm, forecast to be
strong and ending up minor, still may seem fiercer because Earth has
been lulled by several years of weak solar activity.
The storm is part of the
sun's normal 11-year cycle, which is supposed to reach a peak next year.
Storms as large as the latest one will probably happen several more
times as the cycle ramps up to that peak, scientists said.
The region of the sun that
erupted can still send more blasts our way, Kunches said. Another set of
active sunspots is ready to aim at Earth.
"This is a big sun spot
group, particularly nasty," NASA's Hathaway said. "Things are really
twisted up and mixed up. It keeps flaring."
Storms like this start with
sun spots. First, there's an initial solar flare of subatomic particles
that resembles a filament coming out of the sun. That part usually
reaches Earth only minutes after the initial burst, bringing radio and
radiation disturbances. Next is the coronal mass ejection, which looks
like a growing bubble and takes a couple days to reach Earth.
Solar storms have three
ways they can disrupt technology on Earth: with magnetic, radio and
radiation emissions. In 1989, a strong solar storm knocked out the power
grid in Quebec, causing 6 million people to lose power.
For North America, the good
part of a solar storm - the one that creates more noticeable auroras or
Northern Lights - was likely to peak Thursday evening. Auroras were
likely to dip only as far south as the northern edges of the United
States, Kunches said, but a full moon would make them harder to see.
Solar storms can bring
additional radiation around the north and south poles - a risk that
sometimes forces airlines to reroute flights. On Thursday, Delta Air
Lines and United Airlines sent 11 flights to Asia on a more southern
route rather than their more common path over the Arctic. Three American
Airlines flights flew lower than normal over the northernmost parts of
their routes to Japan and China.
___
AP Business Writers Josh Freed and David Koenig contributed to this report.
Online:
NOAA Space Weather Prediction Center: www.swpc.noaa.gov
NASA on solar flare: http://www.nasa.gov/mission_pages/sunearth/news/News030712-X1.5.html
Follow Seth Borenstein at http://twitter.com/borenbears