A comet is heading for a close encounter with the sun later this month, and if it is not vaporised or torn apart, it should be visible to the naked eye in December.

Comet ISON is expected to pass just about 1 million kilometres from the sun's surface on November 28.

Comet ISON is seen in this five-minute exposure taken at NASA's Marshall Space Flight Centre.

Scientists are not sure how ISON will hold up. As it blasts around the sun, travelling at 377 kilometres-per-second, the comet will be heated to about 2760 degrees, hot enough to vaporise not just ice in the comet's body, but also rock and metal.

If the heat does not kill ISON, the sun's gravity may rip it apart. But recent calculations show ISON will survive, scientists said.