Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
by Karen C. Fox for Goddard Space Flight Center
Greenbelt MD (SPX) Nov 27, 2012
The sun goes through a natural solar cycle approximately every 11 years. The cycle is marked by the increase and decrease of sunspots - visible as dark blemishes on the sun's surface, or photosphere. The greatest number of sunspots in any given solar cycle is designated as "solar maximum."
The lowest number is "solar minimum." The solar cycle provides more than just increased sunspots, however. In the sun's atmosphere, or corona, bright active regions appear, which are rooted in the lower sunspots.
Scientists track the active regions since they are often the origin of eruptions on the sun such as solar flares or coronal mass ejections.
The most recent solar minimum occurred in 2008, and the sun began to ramp up in January 2010, with an M-class flare (a flare that is 10 times less powerful than the largest flares, labeled X-class).
The sun has continued to get more active, with the next solar maximum predicted for 2013.
The journey toward solar maximum is evident in current images of the sun, showing a marked difference from those of 2010, with bright active regions dotted around the star.
High resolution imagery from this article is available here.
Solar Science News at SpaceDaily
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|