On February 19 and 20, 2013, scientists watched a giant sunspot form in under 48 hours. It has grown to over six Earth diameters. This image by astrophotographer Paul Andrew shows a detailed, close-up view of this sunspot group, named AR 1678, imaged with a hydrogen alpha filter. NASA said the spot quickly evolved into … Continue reading "Astrophoto: Giant Sunspot Group on the Sun"