A giant NASA balloon is being used to get a good look at Comet Neptune . Comet ISON is nearing Mars on its way toward the sun and will fly about 730,000 miles above the sun 's surface on November 8 . The balloon can rise to 300 feet . Comet ISON could put on show this year .
A giant NASA balloon is being used to get a good look at Comet Neptune . The balloon can rise to 300 feet . Comet ISON could put on show this year .