Changing Planet

Top 5 Comet ISON Questions Answered

Comet ISON, imaged by longtime amateur astrophotograper Damian Peach in the U.K. He used a 4-inch f/5 telescope for 12 minutes of combined exposures on November 15th. Credit: Damian Peach /
Comet ISON, imaged by longtime amateur astrophotographer Damian Peach in the U.K. He used a four-inch f/5 telescope for 12 minutes of combined exposures on November 15. Credit: Damian Peach/

Comet ISON has captured the imagination of astronomers and the public for the past year, and now we can’t let it go.

While the bizarre icy visitor didn’t manage to live up to the hype of “comet of the century,” it left behind a wealth of new data that will keep the scientific community busy for years.

We’ve rounded up some of the top questions many of you have been asking about Comet ISON:

How big was Comet ISON?

Earlier this year astronomers were able to get their first accurate measurements, thanks to Hubble Space Telescope observations, which showed that Comet ISON’s center, or nucleus, appeared to be much smaller than originally anticipated—around 2 to 4 miles (3.2 to 6.4 kilometers) across.

Why the surprise? Because ISON shone so brilliantly while it was still located around the orbit of Jupiter—some 373 million miles (600 million kilometers) from the sun. Researchers theorized that the comet’s brightness meant that the dirty ball of ice, gas, and dust must have been a whopper. Also, Hubble observations made at this time found that the gaseous and dusty coma that surrounded the solid body of ISON measured an incredible 3,100 miles (4,989 kilometers) across.

Will Earth pass through ISON’s remains?

There is no chance of a collision with Earth, since any kind of rubble left behind by ISON will continue to float along its original pathway back toward the outer solar system, which will take it more than 39 million miles (63 million kilometers) away from our planet at its closest approach.

However, Earth may slam into dust clouds trailing in the wake of the comet, along its orbital path.

Astrophysicist Karl Battams said in a blog post about ISON that Earth may encounter these comet remnants sometime early next year.

“The net result of this will be at least one or two, if not a handful, of extra shooting stars in the sky over a couple of nights,” Battams wrote.

“Indeed, Earth passes through numerous comet tails every year—that is what the Leonids and Perseids are, for example. So don’t worry about this, and don’t even expect to notice it.”

Why did ISON not live up to its “comet of the century” billing?

If it had held together during its fiery baptism through the sun’s outer atmosphere, Comet ISON would have had the potential to put on quite a sky show.

However, researchers now theorize that the comet suffered a catastrophic breakup a couple of days before its close passage by the sun. Basically, the intense heat and gravitational pull from the sun pulled the nucleus apart and vaporized its entire ice-water reservoir in a matter of hours.

Any chance we can still see Comet ISON in the sky?

As of December 2, the cloud of debris that ISON left behind shines no brighter than a star of approximately 8th magnitude, one that requires binoculars to view.

That’s because all that is left now is a dust cloud, which is spreading out and becoming more diffuse, with less and less light reflecting off its remaining dust grains. Experts conclude that only wide-angle shots from dark skies may pick up some of the fuzzy patch. And since there is no new source material being pumped into space, Comet ISON is now really an ex-comet.

According to, only “experienced astrophotographers might be able to capture the comet’s fading ‘ghost’ in the pre-dawn sky of early December, but a naked-eye spectacle is out of the question.”

What do astronomers hope to learn from Comet ISON?

Part of what has excited astronomers about ISON is that it originated from the Oort Cloud—a frozen reservoir of billions of comets at the outer edge of the solar system.

And because it was buzzing the sun so closely, it gave scientists a unique opportunity to see outgassing of pristine material from within the comet that originally formed when the solar system was born some 4.6 billion years ago. So expectations are that the mountains of data collected about the comet will offer clues about the chemistry of frozen visitors from the outer solar system such as ISON, and may help answer some of the questions surrounding the birth of planets like Earth.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter and Facebook.

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.
  • Graeme

    You may want to revise this article as part of the comet likely did survive

  • Babu G. Ranganathan

    ASTEROIDS, COMETS, AND METEORS ORIGINATED FROM EARTH: In the Earth’s past there were powerful volcanic explosions propelling millions of tons of earth soil and rock (now asteroids and meteors which may contain organic molecules or organisms) into space. Read my popular Internet article, ANY LIFE ON MARS CAME FROM EARTH. The article explains how millions of tons of Earth soil may exist on Mars, and how debris we call asteroids and meteors could have originated from Earth. According to a Newsweek article of September 21, 1998, p. 12 that quotes a NASA scientist, SEVEN MILLION tons of Earth soil may exist on Mars! How could this be possible? Read and find out.

    Even if the right chemicals exist, life cannot arise by chance. The molecules that make-up life have to be in a sequence, just like the letters found in a sentence.

    Scientist and creationist, Brian Thomas explains:

    “Astronomers measure comets’ masses and erosion rates to calculate potential lifespans. Sun grazing comets last fewer than 100,000 years.2 They thus confront secular astronomy which maintains that comets formed with the rest of the solar system billions of years ago. A solar system that old should have no remaining comets.

    How do secularists solve this dilemma?

    Reporting on Ison, The Independent said, “Comet Ison has taken millions of years to reach us travelling from the so-called Oort cloud – a reservoir of trillions and trillions of chunks of rock and ice, leftovers from the birth of the planets.”3

    Unfortunately, nobody has yet witnessed a single one of those “trillions and trillions of chunks.” Going strictly with observational science, the “so-called Oort cloud” may exist only in the reservoir of the human mind.

    Clearly, secular astronomers invented the Oort cloud to rescue their billions-of-years dogma from a disintegration process that limits a comet’s age—and thus the age of the Solar System—to thousands of years. When Ison becomes visible later this year, perhaps it will remind thoughtful viewers that the universe is quite young, just as Scripture teaches” (Brian Thomas, M.S., Science Writer at the Institute for Creation research).
    Check out my most recent Internet articles and sites: THE SCIENCE SUPPORTING CREATION and WAR AMONG EVOLUTIONISTS (2nd Edition)

    Babu G. Ranganathan*
    B.A. Bible/Biology


    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

  • admiralbrown

    Wow Babu G. Ranganathan don’t let science get in the way of your beliefs. Objects in the Oort cloud rarely interact with anything so their orbits are relatively stable, that is why they have been out there for billions of years. If an Oort object does interact enough to change its orbit then yes as a comet its lifetime may be in the 100,000 year range. But that first step of having an orbit change to take it sunward is the rate determining step and that chance is very small.

  • Makalah

    Im only 11…But this seems so interesting to me its amazing to see what things we can find and how we find stuff like this because its beautiful and amazing … it left me speechless when i saw it as soon as i logged on and i just Peeked my intrest greatly. Ijust want to learn more about it 🙂

  • Makalah

    Who else agrees that this is astonishing??? its marvolious…..AMAZING

  • e11even=E

    @Makalah – Please stay interested and learn as much as you can.

  • Makalah

    Thanks 🙂

  • Smilodon

    I am SO glad that Makalah, at only age eleven is interested in Astronomy and galactic processes. It is hard enough, as a teacher to get girls interested in Science. BUT, it is also one of the most promising avenues for success for girls who get into science, technology and engineering. Brava, Makalah, hang in there . . .

  • El Gabilon

    Poor ISON, as big and as brilliant as you were, like the rest of us the final result is extinction. We had such high hopes of seeing you fly by lighting our sky lifting our thoughts and emotions to a higher level. Alas, that lucky old sun captured you. Rest in Peace!

  • Ed

    OK Babu, you have proven that an otherwise intelligent person can become so single-minded as to focus all of their research to substantiate belief. That is not scientific method, and it’s the same “science” that denies climate change, told us that the Earth was the center of the universe, and once reassured us that tobacco was not harmful. Break your chains and follow the evidence, don’t bend it to your own conclusion.

  • Hello

    Oh so we are safe? I hope so if not I will have a freak out!

  • Leo courageous

    Go to Select the HI1 telescope. Enter 20131202 in the date section, hit submit. Watch the top right corner..ISON is still very much alive

  • ChemE

    “Comet” ISON is very much alive and doing very well, her black hole brane nuclei have created cosmic strings with cusps around the Sun as she continues to discharge her massive energy via radiation to the Sun, our solar brane. Check her out @ darkmattersalot

  • kevin mark bauer

    Why are you still saying Comets are “dirty snowballs ” when they are electrical in nature? Why has NASA provided such poor images and were out classed by the astronomers? Why were NASA Satellites pointed the wrong way when Ison was at Perihelion? Why are NASA scrubbing pictures of what looks to be a planet,that was independently photographed by a ground based telescope when Ison entered Perihelion?
    These are some of the questions I would like answered.

  • Stevie J. Edwards

    “ison-Alpha, clever son of parts unknown. ison-Omega, primordial star infuriate. Wave the dragons trail and graze the brow of Helios! Archaic Drifter ply a heavy sail with eerily infinite heart a feather where common mean sun’s of common light be or vex to nothing passersby? dancer plie with grace so much more then Icarus and solemnly ride the endless tides of time! by: Stevie J. Edwards.

  • Siddhartha Kamilya

    I think that all the planets in this solar system is created from a single object, that may be a star, nebula or anything. That is why cores of all the planets are made of almost same material, even the Geography of the outer surface of the planets are almost same I think earth has no contribution to create ASTEROIDS, COMETS, AND METEORS.

  • duh

    Babu I really hope you do not ACTUALLY have any degrees in any field of science. Way to quote a study from 1998, why not just quote the ancient Greeks and explain how the world is flat and the center of the universe…

  • Mustaq ahmad lone

    no one should near any one who is very higher in class than him or her as ison did so left his siblings came towards a mighty king and as he steped into his yard did not stand before the nighty force so ended his beautiful life which was as old as 4.6 bln years…a tragic…

  • GoD

    please tell me, how many years has ISON been headed towards our star that we call “sun”.

  • nathan

    after three days without water i’m thirsty as hell but this amazing comets has been traveling for 4.6 billion years without losing it’s H2O…why?????

  • Kevin

    You will never see the comet again. It went into the corona of the sun, which is hotter then the visible surface of the sun. sorry to tell you..

  • Kevin

    Siddhartha Kamilya, the reason why we have similar cores is because we were all built from the same dust and clouds… school is great

  • Kevin

    Babu, have you ever heard of escape velocity?

  • Eros Montiel

    Comet Ison did survive, NASA is just lying to us about comet Ison meltdown. Noo!!!! NASA wants people to think that Ison didn’t make it. Here is a link to a video about Comet Ison’s survival Ison also is probably Niburu because how can a comet turn Mars into a comet?

  • Sarah Arnold

    Babu,do you like to share the gospel, too?what’s your religion? please,comment back.

  • Sarah Arnold

    Makaleh,I am only 11 years old,too.Finally,somebody who is my age.

  • Sarah Arnold

    It’s so amazing what God has created for us to enjoy and experience.

  • Elly

    Interesting,people are so much filled with science.BUT,we all have our own sayings about things.Babu is so incorrect that he even needs to go back to first grade.I remember when I was only 3 I wanted to be an meterologist,I guess I look at me now and that dream didn’t come true.
    Thanks,Andrew for the great article

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