Last year's tempest 'most potent' ever measured

The most potent solar storms ever measured squeezed a buffer zone around the Earth, destroying the electronic circuitry of some satellites and sparking spectacular bursts of the Northern Lights, a study says.

The 10-day space tempest in November last year was stirred by huge solar flares - mass ejections of highly energised particles blasted out from the Sun - a few days earlier, reports the British weekly science journal Nature.

American astronomers say the so-called Halloween Storm "compressed dramatically" the Van Allen belts, two magnetic belts which girdle the Earth and protect the planet from electron bombardment by trapping charged particles.