Dark Edge of Sunspots Reveal Magnetic Melee

In what may be one of the most important steps in understanding sunspots since they were discovered by Chinese sky watchers more than two millennia ago, researchers have discovered that the lines of magnetic force that surge out of sunspots appear to peel apart like husk off an ear of corn as some of the lines are dragged back beneath the surface by a sort of solar quicksand. This “quicksand” and the magnetic fields it bends create the penumbrae around some sunspots, the strange rings of mid-darkness that have eluded explanation by astronomers since Galileo first sketched them. With the help of sophisticated computer models and data from solar telescopes that give spectacular views of the sun, researchers at the University of Rochester, University of Colorado, University of Cambridge, and University of Leeds have reported an answer to several mysteries of sunspots in the current issue of Nature.