Calculations show that the celestial visitor could be dazzlingly bright in November 2013 and be easily visible in broad daylight as it rounds the Sun.
Comet ISON is so named because it was first spotted on photos taken by Vitali Nevski and Artyom Novichonok from Russia using the International Scientific Optical Network telescope.
It is currently very faint because it is out in the depths of space near Jupiter's orbit. But it will steadily brighten over the coming months until it passes less than two million km from the Sun on November 28.
That makes it a type of comet called a sungrazer, and there is a risk that the comet - essentially a giant ball of rock and ice, will break up when it makes that close approach.
But it could become brighter than the greatest comet of the last century, Comet Ikeya-Seki, which excited astronomers in 1965.
If it lives up to predictions, it will be many times more spectacular than the last bright visitor, Comet McNaught, which put on a good show by becoming as bright as Venus with a long bright tail from the southern hemisphere in January 2007.
Comet ISON, which has the official label C/2012 S1, appears to be on a nearly parabolic orbit which leads scientists to believe that it is making its first trip through the Solar System. This means it may have been dislodged from a vast reservoir of icy debris surrounding the Sun far beyond the planets, called the Oort Cloud.
It is a giant ball of rock and ice that is likely to be packed with volatiles including water ice that will erupt as brilliant jets of gas and dust when it is at its best.
The comet is likely to remain bright throughout late November and early December if it survives its close brush with the Sun. But astronomers are adding a note of caution by warning that sungrazers can be extremely unpredictable. Comet Kohoutek was a famous example of a comet that failed to live up to the hype in 1973.
Robin Scagell, vice-president of the Society for Popular Astronomy, said yesterday: "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.
"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."
Another comet is also set to put on a resonable show in the night sky next year.
Comet Pan-STARRS (C/2011 L4) which was discovered by an automatic survey from Hawaii in June last year is expected to be bright in the evening sky after sunset next March and as bright as the brightest stars.
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Cool! Definitely want to see that. You may have to install some shutters to be able to sleep at night though.
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