ose 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 spectacular sight in the evening sky after sunset from the UK in late November and early December next year,” Robin Scagell, vice-president of the Society for Popular Astronomy, told the Telegraph.
“Our members will be eagerly following it as it makes its first trip around the Sun and hoping to see it shining brilliantly and displaying a magnificent tail as it releases powerful jets of gas and dust,” he added.
The debate over the brightness should not spill over into any concerns over the comet´s projected orbit. Doomsayers often get excited when new comets are discovered and start rumors of collision courses with the Earth, such as what happened with last year´s comet Elenin.
Comet C/2012 S1 will not even come remotely close to Earth. Even on its nearest approach in January 2014, it will be 36 million miles from Earth, according to comet hunters at Remanzacco Observatory in Italy.
Gray said the best bet is to just sit back, relax and enjoy the show. “I'd give it about a 30 percent chance of being exciting, with a 60 percent chance that I'm wrong. In other words, it'll certainly bear keeping an eye on, but I don't think anyone can say for sure right now.”