Comet ISON

COMET ISON

Named after the International Scientific Optical Network where it was discovered

Comet

An icy body that, when passing close to Sun displays a visible atmosphere (coma) and tail (or tails).

COMETSThe word "comet" comes from the Greek word for "hair.”

Our ancestors thought comets were stars with what looked like flowing hair trailing behind.

COMETS: “DIRTY SNOWBALLS”Comets are loose collections of ice, dust, and small rocky particles whose orbits are usually very long, narrow ellipses.

STRUCTURE OF A COMETA Comet’s Head

Outer layer= Coma (water vapor, CO2, and other gases)

Solid inner core= Nucleus (frozen ice, gas and dust )

COMET’S TAILAs a comet approaches the sun and

heats up, some of its gas and dust stream outward, forming a tail.

Most comets have 2 tails:gas (ion), tail dust tail

Tails point away from the sun because of the force of the solar wind.

A comet’s tail can be more than 100 million kilometers long.

COMET’S TAIL

COMET STRUCTURENucleus

10 km “Dirty Snowball”Coma

Cloud of evaporated ices and ionsmay be 100,000 km in diameter

TailAlways points away from Sun

Solar Wind and Radiation Pressure

THE OORT CLOUD In 1950 Jan Oort noticed that

no comet has been observed with an orbit that indicates that it came from interstellar space,

there is a strong tendency for aphelia of long period comet orbits to lie at a distance of about 50,000 AU, and

there is no preferential direction from which comets come.

ORIGIN OF COMETSMost comets are found in 2 regions of the solar system: Kuiper belt and Oort cloud.

Kuiper belt-doughnut-shaped region that extends beyond Neptune’s orbit to about 100 times Earth’s distance from the sun.

Oort cloud-spherical region of comets that surrounds the solar system out to more than 1,000 times the distance between Pluto and the sun.

So what's special about it? It is thought to be from the Oort cloud It will travel very close to the sun (0.072

AU), nearly 14 times closer to the sun then we are!

If it doesn't break apart, it may be as bright as the Full Moon

It will be visible for several months The entire globe will be able to see it

WHEN FIRST SIGHTED

When first sighted it was 625 million miles away from earth in the constellation of Cancer

WHEN FIRST SIGHTED It measured

18.8 on the reverse scale

(100,000 times fainter than the dimmest star we can see with our eyes)

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 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.

ISON on February 4, March 4, April 3, and May 4, 2013

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 an stretch for millions of kilometers through space.

Comet ISON, discovered 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.

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

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

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.

1.Comet at aphelion

2.Comet at perihelion

3. Sun

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.

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

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 were 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 sky-watcher 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

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

Sunset of 1st December’13 - Western Sky

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

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

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.

The comet will be best seen just before dawn during mid-December. The huge tail will loom in the eastern sky. The tail may be stretched up to BoÖtes or the Handle of the Big Dipper. The comet can be nicely observed, climbing higher in the eastern pre-dawn sky. The comet will shine within 6th magnitude until the month’s end, and so the end of the year. The comet will move from Serpent’s Caput to Draco throughout the month. It will be 5 degrees from the Great Hercules Globular (M13) on December 22nd.

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.

The comet may or may not be very bright; it's tail may be long or short

BUT It will definitely improve our understanding

about Solar System Sun May be life on Earth also

Comet 2013 A1 (Siding Spring) will pass within ~130,000 km on Oct. 19, 2014