India, Aug. 13 -- When the moon slid across the sun on Wednesday, dimming skies from Greenland to Spain, sky-watchers gathered for the spectacle. Scientists, though, were after something else: a few minutes of the rarest laboratory conditions on offer - a clear view of the sun's outer atmosphere, the streams of charged particles pouring off it, and the way Earth's atmosphere reacts when daylight vanishes suddenly.

The August 12 total solar eclipse cut a narrow path of totality across the Northern Hemisphere - through Greenland, Iceland, the North Atlantic, Spain and a sliver of Portugal. Much of Europe, parts of North America and northwestern Africa saw a partial eclipse. India missed the event entirely as the sun was already below the h...