With the onset of winter, I’ve been more interested in following the sun – on and off the web. NASA is a good source of up to date information about science topics, in easy-to-understand formats with lots of colour videos. Just looking at this sunspot from July 2011, for instance, warms me up.
Did you know sunspots increase and decrease in an 11-year “sunspot cycle”? The exact length of the cycle can run as short as eight years and as long as fourteen, but the number and intensity of sunspots increases over time, and then decreases again.
According to NASA, the sun’s poles reverse every 11 years, causing the sunpot activity. Sunspots mark the place of powerful magnetic fields from the sun’s interior, causing solar flares – a phenomenon we’ve been observing since Richard Carrington discovered it in 1859.
Lately we’ve been seeing sunspots and flares more often lately because the cycle we’re in now will peak around 2013 or 2014. Then it will begin to diminish again until around 2020. For more information about sunspots try these links:
Solar flares (November 2011): http://science.nasa.gov/science-news/science-at-nasa/2011/19sep_secretlives/
Sunspot cycles: http://solarscience.msfc.nasa.gov/SunspotCycle.shtml
A unique solar flare (July 2011): http://science.nasa.gov/science-news/science-at-nasa/2011/11jul_darkfireworks/
Marie Powell is a freelance writer and author of Dragonflies are Amazing (Scholastic).