It may not look like much in this sequence of images taken by NASA's Deep Impact spacecraft from a distance of half a billion miles in January, but the comet identified as C/2012 S1 (ISON ...

Comet Ison, which was thought to have vaporized, seems to be alive and kicking. According to NASA on Nov. 29 (KST), the comet was spotted within the sun's orbit. Experts had thought the comet ...