Biggest solar storm in years hits earth

http://www.heraldsun.com.au/news/breaking-news/biggest-solar-storm-in-years-hits-earth/story-e6frf7jx-1226293948495

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.