SUPER-SUNSPOT PREPARES TO DEPART: The biggest sunspot in nearly 25 years is about to leave the solar disk. This picture from Sergio Castillo of Corona CA shows AR2192 approaching the western limb on Oct. 27th:
“For its final trick, AR2192 is going to treat us by mimicking a Giant Skull,” says Castillo, one of many readers who has noted the resemblance between the sunspot and a skeletal face. “Say Happy Halloween as it gets ready to turn away from us. “
As AR2192 approaches the sun’s horizon, it is no longer facing Earth. However, the odds of an Earth-directed radiation storm are higher than ever. The reason is, the western limb of the sun is well-connected to Earth. Solar magnetic fields springing out of that region spiral back to our planet. If a sunspot passing through the area explodes, those spiralling magnetic fields can funnel energetic particles in our direction.
In only a few days, the behemoth sunspot will begin a 2-week transit of the far side of the sun, carried around by the sun’s 27-day rotation. However, that doesn’t mean we’ve seen the last of this magnificent active region. Big sunspots typically persist for two or three solar rotations before they decay. After it leaves, AR2192 will return in November.