The Solar Cycle

Solar Cycles in the News
Solar Cycle Activities

Solar maximum is the term for the maximum in solar activity that takes place approximately every eleven years; solar minimum is the lowest point of solar activity. The last solar maximum was in 2001.

Solar events can interact and interfere with each other, creating a very complex system. Their frequency varies with time. The smaller flares tend to follow the eleven year cycle and peak at several tens of flares per day. The largest flares usually occur only a few times during solar maximum. Sunspots increase with solar maximum, and are relatively rare during solar quiet times. Coronal holes do not last as long during solar maximum.

Monthly averages of the sunspot numbers show that the number of sunspots visible on the Sun waxes, during solar maximum and wanes, solar minimum with an approximate 11-year cycle. Image courtesy of David Hathaway, NASA MSFC.

More about sunspots and the solar cycle...


Back to Solar Activity

December 15, 2008: Space has never been closer -- NASA
December 10, 2008: Sun's cycles can forecast floods, drought? -- National Geographic
November 14, 2008: Solar cycle variations in observed galactic cosmic ray composition -- ACE News
November 7, 2008: The Sun shows signs of life -- Science@NASA
October 13, 2008: Spotless -- HEAPOW
September 24, 2008: Active Region 1002 on an unusually quiet Sun -- APOD
July 11, 2008: What's wrong with the sun? (Nothing) -- Science@NASA
June 9, 2008: Sun goes longer than normal without producing sunspots -- Science Daily
March 31, 2008: Old solar cycle returns -- ESA
March 31, 2008: Cycle 23 redux -- HEAPOW
February 6, 2008: A sunspot in the new solar cycle -- APOD
January 14, 2008: Ulysses spacecraft flies over Sun's north pole -- NASA JPL
January 14, 2008: SOHO: The new solar cycle starts with a 'bang' -- ESA
January 7, 2008: 'Maverick' sunspot heralds new solar cycle -- New Scientist
December 14, 2007: Is a new solar cycle beginning? -- Science@NASA
December 3, 2007: A complete solar cycle from SOHO -- APOD
November 14, 2007: Regional variation in warming from Sun during solar cycle shown by satellite -- Science Daily
August 31, 2007: Celebrating 10 years of ACE in space -- ACE News
July 11, 2007: Study clears Sun of global warming -- Australian Broadcasting Company
May 25, 2007: Astrophysicists find fractal image of Sun's 'storm season' imprinted on solar wind -- EurekAlert!
April 27, 2007: NOAA announces next solar storm cycle will likely start next March -- EurekAlert!
April 25, 2007: The quest to predict the next space "hurricane" season -- NASA GSFC
February 23, 2007: Sol sister -- SpaceDaily

Solar cycle news from 2006 and earlier

Grades 7 - 9: The Sunspot Cycle -- NASA IMAGE