ESA Portal - 14 April 2010 (video available)
Polar skies glowed with ghostly auroras last week during the biggest geomagnetic storm of 2010. The event owed its origin to a solar eruption a few days earlier – revealed here in high-speed detail by ESA’s small Sun-watcher Proba-2.
Eruptions like this one have several components, most notably solar flares and Coronal Mass Ejections (CMEs). Solar flares are caused by sudden impulsive releases of magnetic energy from the surface of the Sun.
The flare seen here took place at 11:54 CET on Saturday 3 April. It was officially classed as ‘weak’, though still involved temperatures of tens of millions of degrees and around the same energy the human race consumes on Earth per year.
Significantly, this eruption was lined up with Earth, sending a vast number of charged particles hurtling towards us. Travelling at around 500 km per second, the front of this CME reached Earth the following Monday, 5 April.
The resulting geomagnetic storm was the most powerful in more than three years. It provoked dazzling auroras but no damage was reported to potentially susceptible systems such as satellites and GPS, communications and electrical power infrastructure.
(ESA / Royal Observatory of Belgium)
Solar storm responsible for the aurora seen here.