Cloud of solar gas strikes our planet
Night skies may light up with auroras
By Marsha Walton
(CNN) -- Airline navigation systems and satellite phones are feeling the effects of unexpectedly turbulent solar weather, but no widespread problems were reported Friday when a cloud of superheated gases reached Earth's upper atmosphere.
Scientists tracking heightened solar activity in recent days reported some commercial airlines have had to make adjustments to their high-frequency communications, or in some cases switch to alternate satellite systems.
"The first thing we notice in these storms is the X-rays, which travel at the speed of light and can cause radio blackouts," said Larry Combs, a space weather forecaster for the National Oceanic and Atmospheric Administration's Space Environment Center in Boulder, Colorado.
Several Himalayan expeditions using satellite phones have also had interference with their communications due to the X-rays, he said.
The X-rays were associated with strong solar disturbances this week, in particular a coronal mass ejection (CME) on Wednesday that sent a stream of energized particles in the direction of our planet.
X-rays reach Earth in a matter of minutes, but CME clouds take anywhere from two to four days. This one began arriving Friday morning, hours earlier than first predicted by space forecasters.
"It's not anything you can see, but it is something our instruments can track," Combs said.
Electrical grids, satellites and pagers and cell phones that rely on orbiting spacecraft can sometimes be affected by CMEs. In 2000, a solar blast briefly knocked out or created steering problems for several orbiting spacecraft.
And in 1989, one zapped the main electrical utility in Quebec, Canada, plunging millions into darkness for hours and costing billions of dollars to fix.
But many electrical systems on Earth and in orbit now have protective systems designed to minimize or prevent damage. And space weather experts like Combs think that this CME storm, classified a moderate 3 on a scale of 1 to 5, will not create major problems.
"After the next 24 hours it may start slowing down," Combs said.
But the sun is in an unexpected phase of energetic activity and could generate more X-rays, bursts or solar storms in the coming weeks, space weather forecasters caution. Sporadic high-frequency radio blackouts are likely to continue, Combs said.
While not as dangerous as a class 5 storm, what makes this one so unexpected is that it comes three years after the peak of an 11-year cycle of solar activity. Combs likens it to a hurricane on the last day of hurricane season.
And like hurricanes, they constantly change in intensity, making predictions a difficult challenge.
"Like anything in nature, sometimes they don't act like we expect them to," Combs said.
The solar stream erupted from a cluster of sunspots on the surface of the sun. The giant dark patch, known as sunspot group 10484, has grown to the size of Jupiter in recent days and has migrated across the face of the sun to a position where it now faces Earth.
Such magnetic storms can also produce spectacular nocturnal displays of the northern lights; NASA's Space Weather Web site is predicting that nighttime auroras could be visible as far south as Oregon and Illinois.
-- CNN.com's Richard Stenger contributed to this report.