Comet ISON Set to Survive Its Pass By the Sun

By Bill Andrews | October 10, 2013 10:05 am
Comet ISON

Comet ISON on the morning of Oct. 8, seen with the 0.8-meter Schulman Telescope at the University of Arizona SkyCenter atop Mount Lemmon. Credit: Adam Block /

While most Americans are looking forward to November 28 this year to (over)indulge in turkey and gratitude, astronomers have another reason to count down the days. That’s when Comet ISON, the Great Comet of 2013, will reach its closest approach to the sun (1.7 solar radii from the solar surface, or about 700,000 miles).

Only then will they know for sure whether the comet will survive its close encounter and go on to provide spectacular views for skywatchers on Earth.

Comet ISON’s Tale

According to a presentation yesterday at a Denver meeting of the Division for Planetary Sciences of the American Astronomical Society (and an upcoming paper), Comet ISON’s future looks bright. Numerical simulations show that its size and density should allow it to escape the sun’s intense heat and gravity without vaporizing or breaking up — a fate that often befalls such “sun grazing” comets.

This is great news for anyone hoping to catch a glimpse of Comet ISON in the night sky. Because of ISON’s orbit,  the best views will occur after perihelion, its closest solar approach. Surviving that milestone practically ensures months of uninterrupted observations of the snowy dirtball.

Of course, you never know. Another study from last week uses detailed observations of ISON’s light to show just the opposite, that the comet will soon “turn off or disintegrate.” And any number of other unknowns — an unusually strong outburst caused by solar heating, say, or a chance collision with an undetected smaller object — could also make ISON’s first pass by the sun a one-way trip.

Look on the Bright Side

Still, scientists aren’t worried. As Nature reported,

But even if the comet disintegrates, there should be plenty of science to do. ISON represents the first time researchers have watched a ‘dynamically new’ comet — a pristine, first-time visitor from deep space that will not return — on course to pass very close to the Sun.

And they’re ready. The long lead-time astronomers have had since ISON’s September 2012 discovery (usually they spot sungrazers just weeks ahead of their perihelion) has ensured steady and sustained observation, including from Mars’ orbit just a few weeks ago.

Of course, while professionals might be okay with ISON’s potentially doomed fate, amateur astronomers (and publications that cater to them) would likely hate to see the “Comet of the Century” fizzle out. It already looks like the comet can’t live up to the initial hype. But, assuming it survives its Thanksgiving visit, ISON could still make for a beautiful sight in the nighttime skies for months to come.

[For more on the science behind ISON, check out our November story about it. And Astronomy magazine has some viewing tips to spot the comet yourself.]

CATEGORIZED UNDER: select, Space & Physics
  • Gary Brannock

    So Ison won’t fall apart when it orbits the sun and heads straight for earth, from which we will pass through it’s 56,000 mile long debris field in January. So tell me once again, just how is this suppose to be a good thing?

    • Andrew

      ISON is a comet and comets are made up of mostly water ice, dust, gasses, and rock.

      At it’s closest to Earth, ISON will be 40 million miles away on it’s return journey past the Earth, where it could possibly exit the solar system.

      Not sure what the problem is.

      • Gary Brannock

        For one thing, a comet cannot be just a dirty snowball and survive an orbit around the sun as they would have us to believe, that’s just preposterous. It’s is a solid mass, which is experiencing an electrical reaction within an electrical universe. And while there may be some gas within it’s 3 mile wide nucleus, if that was all that was fueling it, then it would have burned out long before now. And ISON has recently began causing a large increase in the number and the size of solar flares on the sun as it approaches, and this is at a time when the sun as it’s peak for having solar flares while it’s in the process of a pole reversal. And once ISON has orbited the sun and headed in the general direction of earth, it could possibly attract one of those flares from the sun to be cast in its direction, which means it would also be cast in the direction of the earth, which could cause a major EMP effect. That’s one possible problem. The other possible problem is, that the last time the earth passed by a comet’s debris field right after having flown by, was during the comet Negra in 1347, from which, soon afterwards a plague broke out across Europe, Asia, and China that became known as the black death.

        • Andrew

          Okay Alex Jones. I’m gonna give you a lesson, you can choose to believe it or not but it’s a scientific fact.

          For one thing, a comet CAN just be a dity snowball. This comet does NOT have an orbit around the sun. It’s origin is from outside our solar system, from what is known as the Oort cloud, a sphere of icy bodies that become comets when they get knocked out of their orbit. ISON does NOT orbited around the Sun. This is ISON’s first trip through our solar system. It’s original because it is not like other stargrazing comets, which all follow a similar path (the kreutz path). ISON is going to make 1 trip slingshotting around the Sun and then exit the solar system. It’s been travelling over a million years to do this.

          Second, gas does not fuel a comets propulsion in space. Comets and Asteroids do not fly through space because they have gas or electricity, ok? In space, there is nothing that can slow you down. You will forever travel at a certain speed and gravity from celestial bodies will influence your path.

          Comets and Asteroids have nothing to do with Solar Flares. Flares are a natural part of a star’s life cycle. Every 10 years or so we go through these highs and lows of solar cycles. Stars are colossal nuclear balls of gas.

          Comets and Asteroids are leftover planetesimals, which mean they are the leftovers of planet formation. That’s why they are made up of ice, rock, gas, and dust.

          I did a little research on this comet Negra, and it looks like 90% of the articles about it are all on conspiracy websites. ISON was discovered in September of 2012 and most of the articles about Negra are after this date, and trying to link Negra to ISON only because it was 666 years ago?

          I read some articles on the whole idea that Negra caused the black plague, it was proposed by dendrochronologist Mike Baillie of Queens University, Belfast, Ireland in his book “New Light on The Black Death: The Cosmic Connection” I can’t dismiss this theory, all I have to say about it was that, besides being an interesting read, Negra and the plague was almost 700 years ago so there will likely NEVER be conclusive proof one way or the other, so it’s easy to make claims that sound appealing.

          I know there is no getting through to someone who believes in an Electric Universe, but I tried to be polite and informative. This will be my last reply.

          • Gary Brannock
          • Gary Brannock

            Okay, Mr. thinks He’s Bill Nye science guy, who’s convinced he’s the expert on knowing all the finite details concerning comets because, as you say, you have all the scientific facts. So just where and how did you come by those facts, since no one in the modern scientific world has had the opportunity to make a close observation of a comet, and therefore, to this point all information is based more on hypothetical theories rather than facts. And I’m not sure whether it was a case of intention or ignorance that you singled out specific words and misconstrued the meaning of my sentences. But regardless, Let me be more precise with you, in other words, spell it out. 1st. When I said Ison would complete it’s orbit around the sun, I mistakenly assumed anyone messaging on this site would know I meant once Ison passed behind the sun and sent in the general direction of the earth as a result of the effect of the sun’s gravity on Ison, ie partial orbit. Note: I did not say it was going to crash into earth either, just in the general direction. 2nd. When I stated that Ison had a nucleus only 3 miles wide and that if gas was what was fueling it I was referring to Ison’s 56,000 by 31,000 mile tail, not that it should’ve already ran out of gas and came to a stop like it were a car on earth, duh! And don’t bother to try convincing me it’s tail consist of only dust, gas, and ice, again, it’s nucleus is only three miles wide, if it’s tail consisted only of the elements that make up it’s nucleus, then according to the size of it’s debris trail, it’s nucleus should have broken into billions of pieces a long time ago.
            PS. Although referring to you as Bill Nye was intended as a pun, I was much nicer to you than you were with me, (Alec Jones) Really!!!

  • Deborah Mahmoudieh

    what i am wondering is what made this ‘comet’ suddenly move into our solar system at such a speed? And, did debris fall on Mars? I have seen reports showing Mars flahing and lighting up after Ison passed.


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