It's a galactic survivor. A comet heading straight for the outer layers of the sun on Thursday appeared to have lived through its encounter, astronomers say. The nucleus of Comet ISON, a mall-sized snowball of rock and dust, re-emerged from the area, though it's shedding dust and may not be able to sustain itself. The ever-unpredictable ISON swept 730,000 miles over the sun's surface on Thanksgiving afternoon.
