Despite earlier evidence that comet ISON had burned up and disintegrated during a close encounter with the sun, NASA now believes the comet may have survived the heat. New imagery captured last night shows material from the comet heading up and away from the sun, and scientists believe a small nucleus could still be intact. That's according to "late-night analysis" from scientists that are part of NASA's comet ISON Observing Campaign. Before this latest discovery, a series of images that showed a comet trail (but no comet) led some observers to declare ISON as an "ex-comet."

But NASA says ISON's reemergence continues "a history of surprising behavior" that has seen the comet brighten and dim "in unexpected ways." According to the space agency, these variations in brightness are the result of material boiling off the comet and provide valuable clues as to just what ISON is made of.

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