This image of comet ISON showing its double tail was taken Nov. 10. (Michael Jäger / Spaceweather.com)
Less than three weeks before comet ISON’s closest encounter with the sun, the comet is now sporting a cool double tail.
Like those of most comets, ISON’s dramatic tail is growing as it moves closer to the sun. That’s because the warmth of the sun is releasing gas and dust that were frozen in the comet’s nucleus.
A double tail on a comet is actually not such an unusual thing, said Sky & Telescope senior editor Alan MacRobert in an interview with the Los Angeles Times.
“There is a gas tail and a dust tail to most comets,” he said. “And the gas tail can get more complicated and start to fan out. In just the past few days we’ve seen this structure happen with ISON.”