Massive flares spew billions of tonnes of solar particles towards Earth


IT IS ALL over by now, according to best estimates, so if your electricity wasn’t knocked out or you didn’t see the Aurora Borealis overhead last night, then it is too late to watch how the sun can liven things up on Earth.

The sun kicked out two powerful solar flares on Tuesday, the first at about midnight Irish time, the second about an hour later.

Both blasted out billions of tonnes of solar particles that came streaming towards Earth in what is known as a coronal mass ejection.

The first flare caused considerable excitement for the astronomical community, given it was the second-largest flare seen in the past five years, according to the US National Aeronautics and Space Administration (Nasa).

The leading edge of the first was due to reach Earth some time between 6.25am and 1.25pm yesterday, according to Nasa’s calculations. The remnants of the second likely flowed past us before dawn this morning.

These are the kinds of stellar events that try the souls of power companies, airlines and the owners of satellites. The energetic particles that come with a flare can play havoc with geopositioning systems, with aircraft navigation systems and with radio communications, particularly around the Poles.

The flares, if strong enough, can also cause spontaneous flows of electricity along power cables, causing surges that blow transformers and other power grid equipment.

Yet solar flares are also the events that quicken the hearts of astronomers and the public alike. The arrival of these particles – pulled down into polar regions by the Earth’s magnetic field – triggers the beautiful Aurora Borealis (Northern Lights).

Astronomy Ireland yesterday encouraged people to watch for any sign of the Aurora by keeping an occasional eye towards the northern horizon. The group’s chairman David Moore was fairly confident yesterday afternoon that the flare had already reached us by that time.

“We have been getting magnetometer readings that tell us the Aurora is already under way,” Mr Moore said. It was “anybody’s guess” whether it would produce a light show visible from Ireland but there was every chance, given the exceptional strength of the flare.

The sun releases solar flares over an 11-year cycle that typically rises up to a maximum number of flares and then runs down to a minimum. Mr Moore said we were currently close to the maximum which should be reached next year. “This year and the next two should be very good for flares that produce the Aurora.”

The first flare on Tuesday was ranked as a X5.4 flare, second only to a X6.9 on August 9th, 2011, during the current solar cycle.

The flares as they erupted from the sun were monitored by a collection of satellites including Stereo, the Solar Terrestrial Relations Observatory, Soho, the Solar Heliospheric Observatory, and Goes, a collection of Geostationary Operational Environmental Satellites.

All monitor what has become known as “space weather”, the periodic solar storms kicked off when the sun decides to flare.