entually by the naked eye in early November. Depending on brightness, the comet should remain visible to the naked eye from early November 2013 to mid-January 2014
“In the best case, the comet is big, bright, and skirts the sun next November. It would be extremely bright -- negative magnitudes maybe -- and naked-eye visible for observers in the Northern Hemisphere for at least a couple of months,” Karl Battams, of the NASA-supported Sungrazer Comet Project, told Spaceweather.com.
However, this outcome is far from certain, noted Battams. “Alternately, comets can and often do fizzle out! Comet Elenin springs to mind as a recent example, but there are more famous examples of comets that got the astronomy community seriously worked up, only to fizzle,” he said.
Writing in a blog for the Planetary Society, astronomer Bill Gray pointed out that the comet´s orbit has been very well constrained, but just how bright it will be is anyone´s guess at the moment--“...estimating comet brightnesses a year ahead of time is about like asking who's going to win the World Series next year.”
“It could be astonishingly bright, or it could fizzle. I think it was David Levy (co-discoverer of Comet Shoemaker—Levy 9) who said that comets are like cats: they have tails, and do whatever they want to do,” Gray remarked.
Comets originate from the outer limits of the solar system and are generally composed of icy volatiles such as water, carbon monoxide, carbon dioxide, methane and ammonia. These icy behemoths also contain dust, rocks and any other debris that just happen to be floating around when the Sun evolved. Researchers hypothesize that Comet C/2012 S1 originates from the Oort Cloud, a cloud of frozen comets located about one light year from the Sun possibly containing billions of cometary nuclei that formed during the early days of the solar system when the Sun formed.
“This is quite possibly a 'new' comet coming in from the Oort cloud, meaning this could be its first-ever encounter with the sun,” Battams pondered. “If so, with all those icy volatiles intact and never having been truly stressed (thermally and gravitationally), the comet could well disrupt and dissipate weeks or months before reaching the sun.”
As comets close in on the Sun, the increased solar energy puts stress on the celestial orbiter, causing its frozen volatiles to vaporize, bypassing the liquid phase altogether. Sublimation causes the comet´s gases to erupt, sweeping them back by the solar wind, which forms the tail, the common trait of the comet. Depending on the comet´s chemical elements, the journey past the Sun could make the tail spectacularly impressive.
Of course, this will be dependent on what the exact chemical makeup is and how it formed in deep space. And it is very likely the chemical elements may be just the right mixture that it will cause the comet to erupt, fracture and break apart long before it becomes visible to the naked eye. Or, it may whiz by and release very little material, fizzling any excitement of a spectacular showing.
Due to the comet´s scheduled close inspection of our Sun, it will be, what experts call, a sungrazer. Sungrazers are comets that typically pass within a few million miles of the Sun, with some passing even within a few thousand miles. Famous examples of sungrazers are the Kreutz sungrazers and the Great Comets of 1843 and 1882, as well as the Comet Ikeya-Seki of 1965.
Despite the likelihood of breaking up under the increased solar output of the Sun, there remains a slight chance it could become the brightest comet to scream across the skies in the last hundred years--even brighter than Ikeya-Seki, which dazzled astronomers in 1965.
If it lives up to the hype, it will be far brighter than the last bright visitor, Comet McNaught, which gave earthlings in the Southern Hemisphere a good show in January 2007. But then again, it could peter out like Elenin did in 2011, or more famously, the comet Kohoutek, which failed to live up to predictions in 1973.
“This is a very exciting discovery. The comet looks like it could become a very sp