Thursday, August 05, 2010

Solar blast heading for Earth

In this x-ray photo the dark arc near the top right edge of the image is a filament of plasma blasting off the surface - part of the coronal mass ejection which may trigger a brilliant auroral display. (NASA, AP Photo)

Pietermaritzburg - “Huge solar blast set to hit Earth” read a headline in Tuesday's London Daily Mirror while the Daily Telegraph cautioned “Nasa warns solar flares from ‘huge space storm’ will cause devastation.”

At Tuesday's Witness morning news conference we wondered if we would have any readers on Wednesday. If you are now happily reading this article that means the predicted devastation was greatly exaggerated.

According to the Telegraph it all began with Sunspot 1092, the size of the Earth, which, appropriately enough, popped up last Sunday with a huge flare which astronomers linked to an even larger eruption across the surface of the Sun.

“The explosion, called a coronal mass ejection, was aimed directly towards Earth, which then sent a ‘solar tsunami’ racing 149 million kilometres across space.”

This wave of “supercharged gas” was predicted to reach Earth on Tuesday evening and was expected to bump the magnetic shield protecting Earth. “Scientists have warned that a really big solar eruption could destroy satellites and wreck power and communications grids.”

The specialist website solarcycle24 was more sober in its assessment of the situation: “There will be a chance for minor geomagnetic storming and a small possibility of major geomagnetic storming at high latitudes.”

Which means that those free light shows that get put on by the universe for polar bears and penguins at the poles will increase their wattage and be seen by mere mortals without them having to put on their snow shoes.

Ahead of schedule

What seems to have got everybody excited about this particular solar flare is that it’s ahead of schedule. Solar activity takes place within an 11-year cycle and only at the peak of the cycle are there typically more sunspots and consequently an increase in solar flares.

The peak of the current cycle is not expected until 2013. In June, while everyone was watching the World Cup, Nasa issued a warning stating that their “scientists believed the Earth will be hit with unprecedented levels of magnetic energy from solar flares after the Sun wakes ‘from a deep slumber’ sometime around 2013”.

Well, it seems to have woken up a bit earlier than expected.

“I’m not sitting here quaking in my shoes waiting for something to happen,” said Jake Alletson of the local branch of the Astronomical Association of South Africa.

“Light from sun takes seven-and-a-half minutes to reach us from the sun. Radiation is not much slower so it would have got here by now.” In other words we wouldn’t be speaking to each other over the telephone if it was at significantly higher levels than usual.

“If there is a solar flare it will stimulate the light displays in the southern and northern latitudes,” he said.
Original article.

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