While we’re still in this little pause from the rain showers, run outside and look at the sun. Wait – don’t do that. Better, just take a peek at the above extreme-ultraviolet images of the sun from March 2009 (at left) and March 2011.
The older image, taken by NASA’s Solar and Heliospheric Observatory, presents a relatively placid, drama-free star. But the more recent photo from the Solar Dynamics Observatory shows the sun in explosive disarray, its atmosphere cracked with planet-sized sunspots disgorging megatons of magnetically charged space plasma.
Why the change?
The difference is that in 2009 the sun was at its solar minimum, the quiet phase in its 11-year cycle of activity. Astronomer Heinrich Schwabe noticed in the mid-1800s that periods of solar commotion seemed to always be followed by these moments of calm, a pattern that has held true to the current day.
The sun’s most recent solar minimum was in fact one of its most quiet – the sun was spotless for 266 days in 2008, leading astronomers to dub it the “blankest year of the Space Age.” (A blanker year occurred in 1913 when the sun had 311 blank days.) The sun also experienced a large drop in solar wind pressure and a reduction in its brightness, which caused the earth’s atmosphere to cool and deflate somewhat.
Now the sun is powering up with more storms and flares. Its peak activity is predicted to occur around 2013, but the gas ball is at an impressive boil already. There’s a low-grade G1 magnetic storm in progress that’s causing wild northern lights to be seen as far south as Michigan. And take a peek at these spiraling magnetic loops extending from an active solar region during the first week of April: