These images from NASA's Spitzer Space Telescope of Comet ISON were taken on June 13, 2013, when ISON was 312 million miles (502 million kilometers) from the sun. The lefthand image shows a tail of fine rocky dust issuing from the comet, blown back by the pressure of sunlight. The image at right shows a neutral gas atmosphere surrounding ISON, likely created by carbon dioxide fizzing off the comet at a rate of 2.2 million pounds per day.
A comet that could put on a dazzling show when it zooms through the inner solar system later this year is already blasting out huge amounts of gas and dust, new observations by a NASA spacecraft show.
Images taken on June 13 by NASA's infrared Spitzer Space Telescope reveal that dust and carbon dioxide gas are streaming off Comet ISON, forming a tail about 186,400 miles (300,000 kilometers) long, researchers said.
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