NASA’s SDO observes fast-growing sun spot

Over the course of Feb. 19-20, 2013, scientists watched a giant sunspot form in under 48 hours. It has grown to over six Earth diameters across but its full extent is hard to judge since the spot lies on a sphere not a flat disk.

Fuente : http://www.eurekalert.org/pub_releases/2013-02/nsf…