SHAFAQNA (Shia International News Association) — The sun is in an active part of its 11-year cycle of activity. Throughout 2012, those peering through telescopes with special solar filters have seen dark sunspots dotting the sun’s surface. Space observatories are detecting short-lived but brilliant and powerful solar flares – intense bursts of radiation and our solar system’s largest explosive events – lasting minutes to hours on the sun’s surface. Occasional, powerful coronal mass ejections, or CMEs – giant bubbles of gas and magnetic fields from the sun, containing up to a billion tons of charged particles that can travel up to several million miles per hour – are sometimes released into the interplanetary medium. This solar material streams out through space, and sometimes strikes Earth. Is this dangerous? Should we be worried?
The answer is very likely no. These solar storms are awesome to contemplate, but they are surely not dangerous to our human bodies on Earth’s surface.
What is the danger of a solar storm in space? Very high-energy particles, such as those carried by CMEs, can cause radiation poisoning to humans and other mammals. They would be dangerous to unshielded astronauts, say, astronauts traveling to the moon. Large doses could be fatal.
But, for us on Earth’s surface, solar storms aren’t dangerous because we’re protected by Earth’s blanket of atmosphere. Earth’s atmosphere and magnetosphere protect our human bodies from the effects of solar flares.
On the other hand … solar storms can be dangerous to our technologies. When a coronal mass ejection, or CME, strikes Earth’s atmosphere, it causes a temporary disturbance of the Earth’s magnetic field. The solar storm causes a geomagnetic storm.
The most powerful solar storms send their coronal mass ejections, containing charged particles, into space. As the charged particles slam into Earth’s atmosphere, they can disrupt satellites and bathe high-flying airplanes with radiation. They can disrupt telecommunications and navigation systems. They have the potential to black out entire cities.
But, when a solar storm occurs, it takes several days for the charged particles to reach Earth. When a big coronal mass ejection is on its way, satellites can briefly shut their systems off. Earth-based power grids can be reconfigured to provide extra grounding. And so on.
The current solar cycle – called Sunspot Cycle 24 by space physicists – is expected to peak in early or mid 2013, according to NASA. The number of storms on the sun was high in late 2011 and has been high throughout 2012. Still, according to current predictions, this sunspot cycle is the smallest in over 80 years.
There’s every reason to believe that storms on the sun have been happening for billions of years, since the sun and Earth came to be. If that’s so, then all life on Earth evolved under their influence. So as we approach another peak in activity, the sun isn’t doing anything it hasn’t done many millions of times before. The difference is that now we have technology that can be affected by the sun’s activity.
Bottom line: Storms on the sun are a natural occurrence. They have been happening for billions of years. They are not dangerous to our human bodies on Earth’s surface. But they might be dangerous to some earthly technologies such as those used in telecommunications. The effects of big solar storms have been striking Earth through the past year, with no major ill effects. What’s more, if the effects of a particularly large solar storm were headed toward Earth, we would know several days in advance and have time to prepare.—www.shafaqna.com/english
source: Earth Sky