GREAT SOLAR ACTIVITY: NASA's twin STEREO spacecraft are stationed 150 million miles apart on nearly opposite sides on the sun. Because of their opposing points of view, the two spacecraft normally see different things. The events of Sept. 26th and 27th, however, were not normal. A magnetic filament reared up from the surface of the sun so large that both spacecraft were able to watch it unfold for a whopping 30 hours. Click on the image to launch a 28 MB Quicktime movie:
In the movie, STEREO-A's view appears on the right, STEREO-B's on the left. From one side, the filament appears dark and shadowy, backlit by the fiery surface of the sun below. From the other side, the filament itself appears fiery, outlined by the dark backdrop of space beyond the sun. Astronomers have never seen solar activity in this way before, and there is much to be learned from the increasingly complete view STEREO provides. More images may be found in the STEREO Selects (http://stereo.gsfc.nasa.gov/gallery/selects.shtml)photo gallery.
