by:
By Seth Borenstein in Washington, From AP March 8, 2012 6:50 pm
A solar flare erupts on the Sun's northeastern hemisphere. Picture: AP/NASA
AP
EARTH'S magnetic field is being shaken like a snow globe by the largest solar storm in five years.
After hurtling through space for a day and a half, a massive cloud
of charged particles arrived today and could disrupt utility grids,
airline flights, satellite networks and GPS services, especially in
northern areas. But the same blast also could paint colourful auroras
farther from the poles than normal.
Scientists say the storm,
which started with a massive solar flare early in the week, is growing
as it races outward from the sun, expanding like a giant soap bubble and
moving at 6.4 million km/h.
"It's hitting us right in the nose,"
said Joe Kunches, a scientist for the National Oceanic and Atmospheric
Administration in Boulder, Colorado.
Astronomers say the sun has
been relatively quiet for some time. And this storm, while strong, 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 peak storminess next year. Solar storms do not harm
people, but they do disrupt technology. And during the last peak around
2002, experts learned that GPS was vulnerable to solar outbursts.
Because
new technology has flourished since then, scientists could discover
that some new systems also are at risk, said Jeffrey Hughes, director of
the Centre for Integrated Space Weather Modeling at Boston University.
A decade ago, this type of solar storm happened a couple of times a year, Hughes said.
"This
is a good-size event, but not the extreme type," said Bill Murtagh,
program coordinator for the federal government's Space Weather
Prediction Centre.
The sun erupted on Tuesday evening, and the
most noticeable effects should arrive here between 5pm and 9pm (AEDT)
today, according to forecasters at the space weather centre. The effects
could linger through tomorrow.
The region of the sun that erupted
can still send more blasts earth's way, Kunches said. He said another
set of active sunspots is ready to aim at Earth right after this.
"This
is a big sun spot group, particularly nasty," NASA solar physicist
David Hathaway said. "Things are really twisted up and mixed up. It
keeps flaring."
Storms like this start with sun spots, Hathaway said.
Then
comes an initial solar flare of subatomic particles that resemble a
filament coming out of the sun. That part already hit earth only minutes
after the initial burst, bringing radio and radiation disturbances.
After
that comes the coronal mass ejection, which looks like a growing bubble
and takes a couple of days to reach earth. It's that ejection that
could cause magnetic disruptions today.
"It could give us a bit of a jolt," NASA solar physicist Alex Young said.
The storm follows an earlier, weaker solar eruption that happened Sunday, Kunches said.
Auroras are "probably the treat we get when the sun erupts," Kunches said.
Still,
the potential for problems is widespread. Solar storms have three ways
they can disrupt technology on earth: with magnetic, radio and radiation
emissions. This is an unusual situation, when all three types of solar
storm disruptions are likely to be strong, Kunches said. That makes it
the strongest overall since December 2006.
That means "a whole host of things" could follow, he said.
Solar storms also can make global positioning systems less accurate and cause GPS outages.
The
storm could trigger communication problems and additional radiation
around the north and south poles - a risk that probably will force
airlines to reroute flights. Some already have done so, Kunches said.
Satellites
could be affected, too. NASA spokesman Rob Navias said the space agency
is not taking any extra precautions to protect astronauts on the
International Space Station from added radiation.
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