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Powerful solar flares emitted from sunspots put Earth’s communications, satellites at risk

Earth appears to be right in the crosshairs of a monster-sized sunspot that has shot a series of menacing solar flares aimed squarely at us – but are we really in danger?

All the solar action started early last week on Oct. 19 when the largest sunspot group in a quarter-century slowly began to turn towards the Earth-facing side of the sun. Stretching more than 140,000 kilometers across, the tempestuous AR 12192 sunspot is now as big as the planet Jupiter. That is so large that dozens of Earths could be swallowed up within its fiery borders and it can actually be spotted by sky-watchers placing a solar filter in front of their eyes.

The sunspot has been a busy one too, having blasted six rapid-fire flares into space, three of which have been classified as X-class flares. And it’s these giant solar storms that have the potential to wreak havoc with our communications and power.

Solar flares are giant explosions on the surface of the sun that occur when powerful, twisted magnetic storms above sunspots suddenly snap and release massive amounts of energy into space in the form of radiation from radio waves to X-rays and even clouds of charged particles called Coronal Mass Ejections.

Space weather researchers use a system similar to the Richter scale to classify solar flare strength. Starting from A-class, which are the weakest, each letter represents a 10-fold increase in energy output. So the X-class flares are among the strongest and pack a ten-times more powerful punch than the medium ones. Each letter class it is sub-divided from 1 to 9. These explosions are the most powerful in the entire solar system and can contain as much energy as a billion hydrogen bombs.

The record largest solar flare measured in modern times was in 2003 a blast so powerful that it was off the charts at X28.

If Earth happens to be in the way of one of the solar storms belched from the sun, its radiation can not only create colourful display of northern lights, but also do some real damage in the form of frying satellites, disrupting communications and even bringing down ground-based power grids. One such incident happened back in December 2006 when X-class flares cut out GPS signals for hours.

Already AR 12192 has belched out three X-class flares in just the past three days. And their effects have definitely been felt here on Earth. On Thursday, Oct. 27, an X2 class flare threw copious amounts of X-ray and extreme ultraviolet radiation into space. Travelling at the speed of light, it arrived 8.5 minutes after it was generated. Slamming into Earth’s ionosphere, the solar flare knocked out high frequency radio communications for an hour over much of Atlantic Ocean basin, South America and western Africa.

And this may not be the last we hear of this solar monster. The National Oceanic and Atmospheric Administration (NOAA) predicts that even though the sunspot now is turning away from the Earth, it can still shoot solar storms our way as it continues to grow and grumble. In fact, NOAA predicts a 55% chance for another X-flare within the next 48 hours.

If that holds true there may be more radio blackouts and the possibility of geomagnetic storms lighting up the sky with auroras before the week is out.

In a few days, the sunspot will rotate to the far side of the sun and disappear from view. But with the high level activity and sheer size it has, chances are that we will face the solar beast once again in November.