Comet ISON — officially designated C/2012 S1 — may become one of the most dazzling shows in decades when it nears our sun later this

year.Like all comets, ISON is a clump of frozen gases mixed with dust. Often described as “dirty snowballs,” comets emit gas and dust

whenever they venture near enough to the sun as that icy material transforms from a solid to a gas, a process known as sublimation. Jets powered by sublimating ice also release dust, which reflect sunlight and brightens the overall look of the comet in the sky.

In late November 2013, its icy material will sublimate and release large quantities of dust as the surface erodes under the sun’s

immense solar heat. During this time, the comet may become bright enough to admire with little to no astronomy training and could

potentially be viewable for star-watching in the Northern hemisphere during the day.

Comet ISON is believed to be making its first trip to the sun, and so it is hoped to still have most of its volatiles intact. Volatiles are the

substances which heat up and blast off the comet’s nucleus to form the wispy comet tail which can stretch for millions of kilometers

through space.

Comet ISON, discovered recently by Russian scientists, will be visible in India towards the end of 2013. Experts have opined that the comet that will be seen above the western horizon after sunset is likely to be visible to the

naked eye and could well be brighter than the Moon.

In 2013, astronomy enthusiasts in India would be privileged to witness a great comet

through naked eyes. In November-December, we will be able to see Comet ISON.

Comets are often referred as “dirty snowballs” because they consist of a mixture of ice (both water and frozen gases) and dust. Astronomers

believe these celestial bodies are made up of material left over from the formation of the Solar System almost five billion years ago

Interestingly, comet ISON is following a very similar path to the famous comet of 1680, which was bright enough to be visible in the middle of the

day.

Comet ISON that was discovered in September of 2012. is on somewhat the same trajectory as another famous Comet called the Great comet of

1680 to which a lot of artwork is dedicated, since it was such a big spectacle back then. If it holds together on its journey around the Sun, it

will prove to be the brightest Comet seen in our generation.

Most comets reside in a vast sphere shaped reservoir surrounding the Solar System called the ‘Oort Cloud’

Comet ISON is likely making its first trip to the inner solar system ever, coming to us from the remote Oort Cloud, a refrigerated “storage locker” of trillions of comets gathered into a thick spherical halo at the fringes of the

solar system. The near edge of the Cloud is some 5,000 A.U.s from the sun or 465 billion miles away.

Far from the sun, an icy comet’s temperature hovers around absolute zero (-459 F). If you could see it up close, there would be no fuzzy coma or tail

just an inert hunk of dark ice

For most of 2013, Comet ISON will be a faint telescopic object but its brightness

increases enormously as it approaches the Sun late 2013. Comet ISON reaches

perihelion on Nov 29 when it passes within 0.012 AUs of the Sun. At that time the

comet will appear near the Sun, but it could be as bright as the Full Moon and visible in

the daytime. Quickly moving into the evening sky, ISON could put on a

spectacular show for much of December. On Dec 27, the comet makes its closest approach to Earth at a distance of 0.429 AUs. It will then be 80° from the Sun and well placed in northern skies during the

evening hours.

Comet ISON discoverers Artyom Novichonok (left) and Vitali Nevski

“On Sept. 21,2012 two amateur astronomers from Russia spotted what appeared to be a comet in images taken by a 16-inch (0.4-meter) telescope

that is part of the worldwide International Scientific Optical Network, or ISON, from which the object draws its name.”

Comet C/2012 S1 (Ison) has reasonable chances to become a great comet late in 2013 / early in 2014. Comet ISON (C/2012 S1) has the potential to become a very

bright object that will be well placed for viewing in late 2013.

NASA's iconic Hubble Space Telescope has captured the clearest view yet of Comet ISON, which experts believe could become one of the brightest comets ever

seen when it lights up the sky later this year.

Comet ISON was discovered in September 2012 by Russian amateur astronomers Vitali Nevski and Artyom Novichonok.

Orbital position of C/2012 S1 on 11 December 2013 after perihelion

As mentioned earlier, two astronomers, Vitali Nevski from Vitebsk, Belarus, and Artyom Novichonok from Kondopoga, Russia, discovered the comet on images they obtained September 21,2012. In late 2013, Comet C/2012 S1 (ISON) probably will become the brightest comet anyone alive

has ever seen.

Path of comet C/2012 S1 (ISON) from December 2012 through October 2013 as it passes through Gemini, Cancer, and Leo

BACK ON JAN. 30, NASA’S SWIFT SPACECRAFT AIMED ITS POWERFUL, MULTI-WAVELENGTH EYES AT THE COMET WHEN IT WAS STILL NEAR JUPITER. EVEN AT THAT DISTANCE, SOLAR HEATING VAPORIZED ENOUGH ICE FOR ISON TO

SPEW OUT 112,000 LBS. (51000 KG) OF DUST A MINUTE.

Position of Comet ‘ISON’ during 20th March 2013 - 20th November 2013

On December 8, Comet ISON crosses into the northern sky. It should shine brighter than 1st magnitude and perhaps sport a spectacular tail. Northern

Hemisphere viewers will get increasingly better views as Christmas approaches

Morning of 15th October’13 - Eastern Sky

Viewing of comet is considered to be a treat for eyes for anyone, and it seems that the reality is going to get fulfilled, as comet ISON is going to

come in the inner solar system.

Comet ISON and Mars November 1, 2013, just before Sunrise in the eastern sky (Northern Hemisphere). This occurs slightly after the long-

standing ISON-Mars conjunction in earlier Leo.

November 12, 2013

In the morning sky of 17th Nov.’13, we may be able to witness two comets-ISON near brilliant star ‘Spica’ in constellation Virgo and 2P Encke

near planet Mercury

November 18, 2013

As plotted by the Jet Propulsion Laboratory's "Horizons" system, Comet ISON (C/2012 S1) will pass very close to the Sun — but not crash into it — in late November 2013. At that time it might be at least magnitude –10 — bright enough to be spotted despite very

strong solar glare In fact, the geometry could make C/2012 S1 a "dream comet," as one

eager skywatcher has commented, because it will swing just 40 million miles (0.4 astronomical unit) from Earth a few weeks after perihelion, when it will be high in moonless, northern skies after

sunset and that it could remain visible to the unaided eye from early November to the first weeks of 2014.

Scenario in early morning sky before sunrise on 27th November’13 – Moon, Saturn, Mercury and Comet ISON

It might eject vast jets of gas and dust and be spectacular with a fine tail and even become one of the finest comets ever witnessed by

mankind.

Sunset of 1st December’13 - Western Sky

Comet ISON reaches perihelion (closest to the Sun) November 28 and perigee (closest to Earth) December 26.

Simulation of the orbit of comet C/2012 S1 ISON between 1 November 2013 and 12 December 2013. Earths orbit is indicated in red, and red crosses mark the location of Earth as ISON makes it's close approach.

There's been some speculation on the web that (a) we will cross comet C/2012 S1 ISON's tail, and (b) we will get meteor showers from it.

Earth actually has to intersect a debris trail.Comet tails point way from the Sun, due to the solar wind blowing the

dust and gas away.

National Geographic has stated on their official site that the comet WILL be the brightest in human history and will

be brighter than a full moon.The possibility of the comet being visible in the daytime skies will

make it one of the most exciting comets to whiz past the earth in a long while.

At  its perihelion (its closest point to the sun), due on November 28, 2013, the comet will come within 18,00,000 kilometers of the sun’s

surface and could evolve into a dazzling celestial body, possibly bright enough to be visible in broad daylight