Sunspot AR 12192 is the largest such feature seen on the surface of our stellar companion in 24 years, forming several flares that could affect the Earth, possibly wiping out electronics and communications.
The strongest flare from the sunspot was recorded on October 24, and designated as a X3.1 event. These X class flares are the most powerful, and the number following the letter is a sub-classification, also denoting strength. An X3, for instance, is twice as powerful as an X2.
"NASA's Solar Dynamics Observatory, which watches the sun constantly, captured images of the event. 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," NASA officials wrote on a Web page announcing detection of the powerful flare.
This solar flare, which peaked at 5:41 p.m. EDT on Oct. 24, was the fourth such X-class event recorded by astronomers since October 19.
On October 25, another flare was seen erupting from the sunspot, suggesting any problems with radio signals or satellites could unfold over a significant amount of time.
"Region 2192 produced another R3 radio blackout (X1 flare) today. It was a long duration event, beginning at 12:55 pm EDT, peaking at 1:08 pm and ending at 2:11 pm. This was the fourth R3 event from this region, the largest region in area in nearly a quarter century. No significant coronal mass ejections have been observed," National Weather Service managers reported in a statement on the event.
The Solar Dynamics Observatory, which recorded the sunspot and resulting flares, was launched in February 2010, to study the solar surface and surrounding atmosphere.
The sunspot is about 800,000 miles across, large enough to allow ten Earths to fit side-by-side along its greatest length. The diameter of the sunspot is about the same as the largest planet in the solar system, Jupiter. The last time astronomers noted a sunspot of this size was in November 1990.
These powerful flares have the power to disrupt communications among satellites, although the magnetic field of the Earth protects life on the surface. However, none of the flares recorded by researchers appear to be headed in our direction.
The Carrington Event, also known as the Solar Storm of 1859, was the most severe encounter Earth has had with such flares in recent history. Telegraphs sent off sparks, injuring operators, and some continued to transmit, even after being disconnected from electrical sources. Modern society, now much more dependent on technology than the world was 155 years ago, could suffer far greater effects in the event of a similar strike from the Sun.
