A comet is heading for a close encounter with the sun later this month, and if it is not vaporized or torn apart, it should be visible to the naked eye in December.
Comet ISON is expected to pass just about 621,000 miles (1 million km) from the sun's surface on November 28.
Scientists are not sure how ISON will hold up. As it blasts around the sun, traveling at 234 miles per second (377 km per second) the comet will be heated to about 5,000 degrees Fahrenheit (2,760 degrees C), hot enough to vaporize 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 say.
"If Comet ISON survives intact, then yes, we'll have a nice show later on in the month. If it actually crumbles into pieces, in some ways that's better for scientists because we will be able to see inside the comet and see what the chemistry is like," said NASA scientist Michelle Thaller.
This is the comet's first foray into the inner solar system - which, according to NASA, means it is still made of pristine matter from the earliest days of the solar system's formation. Its top layers have never been lost by a trip near the sun.
"This is a preserved bit of the early solar system and we really want to know what conditions were like four and a half billion years ago," Thaller said.
NASA scientists say ISON poses no danger for Earth.
"The closest approach to Earth will be in late December and it will get about 40 million miles (64373760 km) away from us and even if the comet does break up into many chunks, all those chunks will keep going by in about the same orbit. It’s actually not going to get anywhere near us, so just enjoy it, don't worry about it, this is a true gift from the cosmos," Thaller said.
The comet was discovered in September 2012 by two amateur astronomers using Russia's International Scientific Optical Network, or ISON, for which the comet is named.