Sunspots. SOHO image of an enormous sunspot group (dark,upper centre) on the surface of the Sun. Sunspots are relatively cool areas on the Sun's surface associated with strong magnetic fields. At the end of March 2001,the area of this sunspot group was over 13 times that of the surface area of the Earth,making it the largest sunspot group seen during that solar cycle. Sunspot numbers vary over an 11 year cycle,for reasons that are not completely understood. Image taken by the Michelson Doppler Imager on board the SOHO (Solar and Heliospheric Observatory) spacecraft | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Soho / NASA / ESA / SOHO |
Taille de l’image : | 2100 px × 2097 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |