Changes

The '''sunspot cycle''' is a periodic variation in the number of [[sunspots]]. Over the last {{years ago|1755}}, 23 of these have been observed with an average length of 11 years.<ref>"The number of sunspots reaches a maximum about every 11 years ..." [http://zebu.uoregon.edu/~soper/Sun/cycle.html Davison E. Soper, Institute of Theoretical Science, University of Oregon]</ref>

The '''sunspot cycle''' is a periodic variation in the number of [[sunspots]]. Over the last {{years ago|1755}}, 23 of these have been observed with an average length of 11 years.<ref>"The number of sunspots reaches a maximum about every 11 years ..." [http://zebu.uoregon.edu/~soper/Sun/cycle.html Davison E. Soper, Institute of Theoretical Science, University of Oregon]</ref> A period of time when there are few sunspots is called a ''solar minimum''. The longest one was the [[Maunder Minimum]], and it corresponded with the [[Little Ice Age]] (1650 to 1850).<ref>"That period also correlates with the Little Ice Age, which started in 1650 and ended in the mid-1800s." [http://www.santafenewmexican.com/HealthandScience/A-quiet-sun Low sunspot cycle fascinates scientists, who say there's no reason to panic] - Santa Fe New Mexican</ref>

==Notes==

==Notes==

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