Freak solar explosion disrupts satellites

Communication systems are being disrupted by the effects of an unusually large solar explosion that started lashing the Earth this week. The explosion could also cause spectacular auroras in the night skies as far north as Sydney, weather permitting.

Dr David Cole, director of the Australian Government's space weather service, says the massive solar explosion as the Sun is supposed to be in a fairly quiet phase.

"We didn't expect anything in particular and suddenly this turns up and it's really fierce," says Cole, of IPS Radio and Space Services in Sydney.

When magnetic fields in the Sun coalesce in dark regions called sunspots they can explode sending a blast of radiation. Such solar flares reach Earth within minutes. This is followed by a cloud of plasma or coronal mass ejection (CME) that takes a day or so to reach Earth. The flare and CME alter the ionosphere, the outermost part of Earth's atmosphere, and cause problems with communication systems.