A very large solar eruption just occurred on January 13, 2013, in the early morning hours. The Earth-directed coronal mass ejection, or CME, is very likely to trigger a strong Northern Lights display this week, researchers from NASA say. But not powerful enough to cause problems for satellites or other electronics.
A CME, which is something quite different from a solar flare, is a not entirely understood phenomenon that occurs on the Sun, and on other similar stars. Essentially, it’s an eruption that fires huge amounts of solar particles off into space, and hits whatever planets, asteroids, meteor shower causing debris, or comets, that are in the way. It typically takes around 1-3 days after the CME explodes for it to hit the Earth.
“Experimental NASA research models, based on observations from the Solar Terrestrial Relations Observatory (STEREO) and the ESA/NASA mission the Solar and Heliospheric Observatory, show that the CME left the sun at speeds of 275 miles per second. This is a fairly typical speed for CMEs, though much slower than the fastest ones, which can be almost ten times that speed.”
CMEs that impact the Earth are capable of causing great damage to the rather fragile, and overcomplicated, infrastructure of modern civilization. In the very limited timespan that we have been using an electric grid we have already experienced two very significant instances of large CMEs impacting the Earth.
The first, the March 1989 event, caused several billion dollars worth of damage, and the entire collapse of Quebec’s power grid for 9 hours. If such an event were to occur today, the damages and costs would be much higher.
Number two, the solar storm of 1859, completely dwarfs the 1989 event though. It was so powerful that aurora were seen all over the world, as far south as the Caribbean, and bright enough to awaken people, who thought that it was day. Telegraph systems all over the world failed, in some cases even shocking people and sparking, caused large fires. Even when disconnected from their power supply they continued to operate on their own.
There is also evidence that solar storms 10-20 times stronger than the 1859 storm are possible on the Sun, and strong evidence that one occurred in 774 AD.
CMEs the size and speed of this recent one, though, have generally not resulted in significant geomagnetic storms. “They have caused auroras near the poles but are unlikely to affect electrical systems on Earth or interfere with GPS or satellite-based communications systems.”
“Two active sunspot regions — named AR 11652 and AR 11654 by the National Oceanic and Atmospheric Administration (NOAA) — have produced four low-level M-class flares since January 11th. Solar flares are powerful bursts of light and radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however, when intense enough, they can disturb the atmosphere in the layer where GPS and communications signals travel. M-class flares are the weakest flares that can still cause some space weather effects near Earth. The recent flares caused weak radio blackouts and their effects have already subsided.”
Source: NASA/Goddard Space Flight Center
Image Credits: NASA/STEREO; NASA/SDO/HMI