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“Once in a Civilization” Comet to Zip past Earth Next Year

The views expressed are those of the author and are not necessarily those of Scientific American.

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Comet Hartley 2

Close, but not this close

As it flares out of the distant Oort Cloud, the newly discovered comet C/2012 S1 (ISON) appears to be heading on a trajectory that could make for one of the most spectacular night-sky events in living memory. Why is this comet expected to be so unique? Two reasons:

Astronomers predict that the comet will pass just 1.16 million miles from the Sun as it swings around its perihelion, or closest approach. (This may seem like a lot, but remember—the Sun is big. If we were to scale the Sun down to the size of Earth, the comet would pass well within the orbits of dozens of satellites.) The close approach will melt enormous amounts of the comet’s ice, releasing dust and gas and forming what should be a magnificent tail.

After it loops around the Sun and forms this tail, the comet should then pass relatively close to Earth—not near enough to cause any worry, but close enough to put on a great show. Viewers in the Northern Hemisphere will get the best view as the comet blooms in the weeks approaching Christmas 2013. The comet could grow as bright as the full moon.

Of course, comets have a habit of not living up to expectations. This one could be sucked into the Sun during its close approach, or not grow as much of a tail as astronomers hope.

But that hasn’t dampened enthusiasm for what Astronomy Now is awkwardly calling “a once-in-a-civilisation’s-lifetime” event. The comet expert John E. Bortle is already comparing ISON with the Great Comet of 1680, which, according to contemporary accounts, caused the people of New York’s Manhattan Island to be “overcome with terror at a sight in the heavens such as has seldom greeted human eyes….  In the province of New York a day of fasting and humiliation was appointed, in order that the wrath of God might be assuaged.”

We can only hope for such a show.


Image of comet Hartley 2 courtesy NASA/JPL-Caltech/UMD

About the Author: Michael Moyer is the editor in charge of space and physics coverage at Scientific American. Follow on Twitter @mmoyr.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. RSchmidt 11:43 pm 10/5/2012

    “In the province of New York a day of fasting and humiliation was appointed, in order that the wrath of God might be assuaged.” well common now, this is the year 2012. The year 1680 was a long time ago. I would only expect the republicans to act like that now. On the upside, if Romney gets elected we can tell the people that the comet is a symbols of gods wrath for voting him in and perhaps they will sacrifice him on an alter. Or perhaps we can just tell him it’s his mother ship come to get him and we can send him to meet it.

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  2. 2. alan6302 2:23 pm 10/6/2012

    Nostradamus predicted a comet associated with the big events. The description of the comet seems to be C o ME t. Another words he disguised a CME event in the word comet.

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  3. 3. kongrooo 5:35 pm 10/6/2012

    Sometimes dude you just have to roll with it man!

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  4. 4. Obbop 5:50 pm 10/6/2012

    Pondering chaos theory, string theory, quantum mechanics and the Borg I envision a gentle nudge at the appropriate time and place causing an impact event that will eliminate the human species and other vulnerable life forms allowing the easy settlement of folks desiring a nice planet to reside upon.

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  5. 5. ErnestPayne 2:52 pm 10/8/2012

    Aha. December, 2013. The Mayans were only out by a year. j/k but stand by for the “end of earth” crowd to go nuts.

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  6. 6. American Muse 8:15 pm 10/10/2012

    “When beggars die there are no comets seen;
    The heavens themselves blaze forth the death of princes.”

    Julius Caesar (II, ii, 30-31)

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  7. 7. AJRussell 3:41 pm 10/11/2012

    Alas, the Mayans were correct, the world is coning to an end; not!
    This should be a tremendous holiday season with the extraordinary light show!

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  8. 8. David Illig 3:43 pm 10/11/2012

    Nostradamus? Why does a simple natural phenomenon have to bring out the nut cases? It’s a comet, not a deep mystery. My five-year-old nephew and my 90-year-old mother are both able to predict that there will be comets. So what?

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  9. 9. bucketofsquid 5:54 pm 10/11/2012

    This sounds great. Hopefully all the nut jobs will work themselves into a frenzy of self destruction. That will leave the rest of us better able to move on into the remainder of this century without some of the needless distractions.

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  10. 10. veronica_tg 6:20 pm 10/11/2012

    Yes, Mr. Schmidt, if Mitt gets elected how can we insure that he meets this comet, in outer space, that is.

    Loved your comment

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  11. 11. PeterT 6:26 pm 10/11/2012

    Once again, SCIAM, your e-mail button goes No-Where!!

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  12. 12. Steve D 9:40 pm 10/11/2012

    The two most irresponsibly hyped celestial events are meteor showers and comets. The comet may be brighter than magnitude -10 when closest to the Sun, but a small patch of sky a degree from the Sun can be that bright. So viewing the comet in daylight is out of the question for most people. If the comet isn’t magnitude zero and more than thirty degrees above the horizon in a dark sky, like Hale-Bopp in 1997, it will be a dud for most people. It looks like the comet may be well placed after closest approach.

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  13. 13. segesta77 10:43 am 10/13/2012

    RSchmidt: sigh, it’s only Michelle Obama that wants me to fast, and the TSA that wants to humiliate me.

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  14. 14. Ritchie The Riveter 11:31 am 10/13/2012

    segesta77 … you are more right than you know; the Progressives that want to dominate our government seek to jam their socio-economic morality down our throats with a fundamentalist zeal that makes Baptist preachers look like libertines out for beads at Mardi Gras.

    RSchmidt … “The year 1680 was a long time ago. I would only expect the republicans to act like that now.”

    As opposed to the panic of the Climate Change Cult with respect to the impending destruction of our planet unless we submit to their faith NOW … our living standards and ability to pursue happiness be damned?

    OTOH, the evangelical Christians you loathe, RSchmidt, are not worried about this comet in the least … for as we see what’s in the Bible, there’s a lot more to happen before this planet’s destroyed. Not to mention that, despite rumors to the contrary, we are a highly-independent sort that is not afraid to challenge, or even ignore, those in leadership positions that you might think would lead us to Jonestown or Hale-Bopp.

    “On the upside, if Romney gets elected we can tell the people that the comet is a symbols of gods wrath for voting him in and perhaps they will sacrifice him on an alter.”

    As opposed to informing the people of the bullet they were able to dodge thanks in part to the exposure of the mendacity surrounding the East Anglia CRU … reminding them of the proper application of the scientific method and the need to state fact as fact, theory as theory, and faith as faith, regardless of “consensus” on the subject at hand … especially when it comes to using the subject as the basis for setting public policy?

    “Or perhaps we can just tell him it’s his mother ship come to get him and we can send him to meet it.”

    When that ship comes a’calling, they will step out with a sign like the chauffeurs hold up at the airport … and that sign will read … Joe Biden.

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  15. 15. tanyah 10:20 am 10/14/2012

    Rschmidt, you made a typo; you spell altar for religious use with an “ar” not “er”. Sorry you have to bring in politics, Democrats are aways doing that, it defines who they are.

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  16. 16. Bird/tree/dinosaur/etc. geek 6:26 pm 10/14/2012

    @ Richie the fundie troll:
    Your moldering religious book is a pile of horse dung. Much of the Old Testament is political propaganda written by a courtesan at the court of Solomon.

    As for your complaints about liberals: don’t make me laugh.

    If you need a tinfoil hat, I can supply you with a “Paranoia Deluxe” model with a reinforced frame and a pair of soda-drinking attachments for the low price of $99.99. The Paranoia Deluxe is guaranteed to stop 97% of mind-reading and mind-influencing rays, from both governments and aliens. With the ParanoiaGoggles accessory ($49.99, but discounted to $37.75 when purchased with the Paranoia Deluxe), you are guaranteed to be protected from 100% of mental scanning rays, although you may not be able to see (since tinfoil goggles are opaque).

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  17. 17. justyntoo 9:26 pm 10/14/2012

    i saw halley’s comet , and hale-bopp , and view the heavens with awe and wonderment at its beauty and mystery , but , if this comet were to not merge with the sun and if the gasses given off were to be extra-ordinary , and if it were to pass very close to the earth , then – one might be concerned that when a comet travels from the sun then the tail is pointing a way and what if the earth were to pass thru its wash ? i hope its water vapor and co2 . and not cynide . but hey , then who ever is president may be able to blame god’s justice .

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  18. 18. justyntoo 9:33 pm 10/14/2012

    sorry , just a by , wasnt there supposed to be an asteroid and a comet that were traveling in such a way as to be scheduled to pass very close to the earth around feb-march of 2013 ? if i remember , the comet was found in 2010 and the asteroid was found in 2012 . this is shaping up to be a very active year .

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  19. 19. JerryC 5:46 am 12/25/2012

    @RSchmidt, you do understnad why your comment is totally out of line don’t you?

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  20. 20. donim 7:10 pm 12/27/2012

    Comets are not snow and ice. What a joke. thunderbolts dot info proves different. Even NASA has shown pictures of a comet up close and it was just a rock, hot even.

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  21. 21. showmemike 12:01 pm 12/30/2012

    COMET ISON may be the return of the STAR OF BETHLEHEM

    the orbit of COMET ISON brings it back every 333 years,
    so it can be established that the comet was here in 15 a.d.
    considering that an exact year has never been established
    for the birth of christ,
    is it more than coincidence that
    there was a census in 14 a.d. called by Caesar Augustus?

    you heard it here first !

    Link to this

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