HUNTSVILLE, Ala. – The sun might be getting ready to flare up, solar scientists say.

Although the orange ball of burning gas has been relatively calm over the past few years, sunspots recently popped up and spewed out solar particles.

The ejection missed the Earth, but solar observers are starting to think the sun’s activity cycle is headed back to more disruptive sunspots and ejections, said Dr. David Hathaway, a solar physicist who studies the sun for the National Space Science and Technology Center in Huntsville.

“The sun is at a critical point in terms of activity and observations,” Hathaway said. “We are starting to see new sunspots that could be part of a new cycle of activity.”

The sun goes through roughly an 11-year cycle of minimum and maximum activity. It peaked in 2001 and early 2002, but now the activity could be starting to kick up again, Hathaway said.

“It’s still within a couple of years away, but the activity is picking up, we think,” he said.

How troublesome can the sun be?

When the sun flings out particles via what scientists call a “coronal mass ejection,” or solar flares, many times the plumes engulf the Earth. Much of it is blocked by the planet’s magnetosphere, but the particles can disrupt communications satellites, knock out power grids and affect astronauts on the International Space Station.

Airline traffic over the poles can be affected because those flights are out of range of orbiting communications satellites and have to rely on radio, Hathaway said. “It’s a big, big concern among several industries,”

In 1989, power grids in North America – mostly the eastern United States and Canada’s Quebec province – were shut down by solar activity.

People were without power for days, Hathaway said.

“When it hits people at home like that, they sort of start to wake up and realize “Hey something is going on here with the sun and it affects me.’ That’s when they turn to us for better predictions,” Hathaway said.

In 1998, telecommunications satellites were disrupted by the sun, causing failures that affected businesses accepting credit and debit cards. “This cost millions in lost business, and much more attention was paid to the sun,” Hathaway said.

Now, several probes monitor the sun, allowing scientists to give an early warning when sunspots or ejections might affect Earth.

“We’ve gotten so much better at accurately predicting what the sun can do and when it will do it,” Hathaway said.

Satellites can be put into a safe mode to protect vital instruments “and the power companies know to back off the usage on their grids, which keeps them from going off-line,” Hathaway said.

PH END SPIRES

(Shelby G. Spires is the aerospace writer for The Huntsville (Ala.) Times. He can be contacted at shelby.spires(at)htimes.com.)

2008-04-07-SUN-ACTIVITY

AP-NY-04-07-08 1511EDT