We discussed the ISON ISOFF again nature of comet ISON in this WUWT thread, now it looks like ISOFF again.
From NASA’s Spaceweather.com (h/t Fernando): Comet ISON is fading fast as it recedes from the sun. Whatever piece of the comet survived the Thanksgiving flyby of the sun is now dissipating in a cloud of dust. (animation follows)
(Note: The animation may take a minute or more to load, based on your Internet connection speed.) Click to view a 3-day movie centered on perihelion (closest approach to the sun):
This development makes it unlikely that Comet ISON will put on a good show after it exits the glare of the sun in early December. Experienced astro-photographers might be able to capture the comet’s fading “ghost” in the pre-dawn sky, but a naked-eye spectacle can be ruled out.
On Nov. 29th, pilot Brian Whittaker tried to catch a first glimpse of Comet ISON from Earth, post-perihelion, from a plane flying 36,000 feet over the Arctic Circle in northern Canada. No luck:
“Ideal viewing conditions from the Arctic revealed no Comet ISON,” reports Whittaker. “This negative report is to quench the thirst of other fellow dreamers under cloudy skies or further south. Later I could see that SOHO showed the comet dimming further.”
Despite Whittaker’s negative result, it is too soon to rule out observations from Earth as the twice-dead comet moves away from the glare of the sun. Meanwhile, NASA’s fleet of solar observatory will be tracking the remains.
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Sparks says:
December 1, 2013 at 11:58 am
I did mention ‘molecules’ three times in my comment, which are set-apart from ions by their lack of electrical charge in context
????
Leif,
Oh, I see it now lol
How about this;
TAKE TWO
All comets are electrically neutral and remain electrically neutral when they interact with the suns magnetic field, when a comet is traveling towards the sun it begins to experience ionization, the rate of which, increases the closer to the sun it gets, this ionization process on a comet is actually all the atoms or molecules trying to magnetically align them selves with the suns magnetic field, this results in an ion tail as atoms or molecules near the surface of the comets nucleus become lose and begin to free them selves from the parent comet, this also produces turbulence which causes larger dust particles and ice (which have a greater number of atoms or molecules) to become lose from the parent body where they separate and eventually become neutral or balanced with the suns magnetic field.
Sparks says:
December 1, 2013 at 12:09 pm
How about this; TAKE TWO
this ionization process on a comet is actually all the atoms or molecules trying to magnetically align them selves with the suns magnetic field..
No good. By being ionized, the comet material becomes a conductor and as such can interact with a magnetic field [currents can be induced, etc], specifically the matter gets attached [‘frozen in’] to the solar wind magnetic field and as the latter streams past the comet at 400 km/sec, the comet matter follows and forms a tail which then also moves at 400 km/sec away from the comet. In this way the existence and the speed of a solar wind was first deduced in 1951.
TAKE THREE,
All comets are electrically neutral and remain electrically neutral when they interact with the suns magnetic field, when a comet is traveling towards the sun it begins to experience magnetic induction, the rate of which, increases the closer to the sun it gets, this ionization process on a comet is actually all the atoms or molecules trying to magnetically align them selves with the suns magnetic field, this results in an ion tail as atoms or molecules near the surface of the comets nucleus become lose and begin to free them selves from the parent comet, this also produces turbulence which causes larger dust particles and ice (which have a greater number of atoms or molecules) to become lose from the parent body where they separate and eventually become neutral or balanced with the suns magnetic field.
Sparks says:
December 1, 2013 at 12:21 pm
TAKE THREE
NFG
TAKE FOUR
All comets are electrically neutral and remain electrically neutral when they interact with the suns magnetic field, when a comet is traveling towards the sun it begins to experience magnetic induction, the rate of which, increases the closer to the sun it gets, this process of magnetic induction on a comet is actually all the atoms or molecules trying to magnetically align them selves with the suns magnetic field, this results in an ion tail as atoms or molecules near the surface of the comets nucleus become lose and begin to free them selves from the parent comet, this also produces turbulence which causes larger dust particles and ice (which have a greater number of atoms or molecules) to become lose from the parent body where they separate and eventually become neutral or balanced with the suns magnetic field.
Sparks says:
December 1, 2013 at 12:24 pm
TAKE FOUR
Still NFG, here is what happens: http://en.wikipedia.org/wiki/Comet#Coma_and_tail
lsvalgaard says:
December 1, 2013 at 12:27 pm
“Still NFG…”
It says on wikipedia: “solar radiation causes the volatile materials within the comet to vaporize and stream out of the nucleus, carrying dust away with them…”.
i gave a better explanation, and implied that the process is magnetic in nature!
It did not. The solar wind magnetic field if reversing directions [does that two to four times per month] it can steal the comet’s tail. We have observed thousands of comets and the tail behavior is well-studied and well-understood. ISON is not special as far as I can see.
Yes, it looks like NASA got it wrong there with that massive supersonic explosion in their model. But no need for detail other than ask why did NASA plonk such an event in their model?
The flaw in this argument is your assumption that the tail is a stiff, rigid rod.
In theory its not a rod. But a tail can approximate a rod if the matter is ejected from the nucleus with high enough velocity to make other factors negligible.
And what do we see with Ison? After perihelion, the ion tail is curved until about 04:00UT from the COR2-A view, after which it is a good approximation to a rod. We would expect this because the gravity acceleration and comet velocity which had become significant during perihelion weaken, therefore the nucleus emission velocity of tail material returns to being the only dominant factor in shaping the tail, just as before perihelion. The rod-like ion tail ends up at around 70degree off the angle predicted by conventional theory. On the LASCO view the angle is greater, about 80degrees. The COR2-B view has the tail spinning towards radial alignment. But since a line that isn’t aligned on a point will still appear to be aligned from some angles, we can expect this, but since it isn’t aligned from other perspectives, we should know it doesn’t mean its aligned.
Aaaaanyway, I was ideally hoping to lead a few of the open minded viewers to the correct answers via some common sense questions and their astute inquisitive nature.
But its moving slowly, so I’ll just tell you what’s actually happened with Ison’s tails.
Over the last 20 years comets were observed by probes to have active jets. The photos were clear cut evidence that ion tails weren’t produced by the solar wind blowing off dust and ice, but by these jets on the comet.
http://news.sciencemag.org/sites/default/files/styles/thumb_article_l/public/article_images/sn-hartley.jpg
http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2010/11/Hartley-2-close.png
Convention says the jets are powered by trapped pressured gas within the comet. EU says they are ion jets because the comet is highly electrically charged ( debye shield stops short out discharge )
Given a time period over days or weeks, these ion jets often prefer to align with the solar wind, and often they become strengthened in power\luminosity when they are aligned.
For Ison, the ion jet alignment was lost at perihelion. The comet spun and with it so did the direction of ion jet ( for its position and direction is fixed to the comets surface ), but it spun out of alignment, ending up 70-80degrees off. Once out of alignment with the solar wind, the jets lost power.
This offers a better explanation why the angle was wrong, and why the comet’s light died – because it span into an angle such that its jets were not aligned with the solar wind.
Note that conventional theory can’t explain too well why comets light up and go off.
Also time for this….
EU based predictions
We’re in a fun time right now because next month Ison flys past Earth. Great time to make predictions to be tested soon!
For a comet to light up, it needs to have jets aligned with some electro-magnetic energy source. Most obviously, the solar wind. Ion jets ‘want’ to grow and become prominent as the comet become electrically charged. On the way in, Ison got pretty bright. But will it do so on the way out ?
Yes.
Why?
– It will be travelling thru the same region of space as the space which charged to brightness.
– 2ndly, from the evidence at perihelion, Ison isn’t spinning much. No spin lets the jets grow on one region of the comet. Ison wasn’t spinning with its axis tangential to the sun on the way in.
– It will be brighter than on the way in. This is often the case with comets. But not because its warmer as convention says, but because the solar wind and solar magnetic field is stronger closer to the sun, and charges the comet harder.
CMEs and solar wind shockwaves can pop a comets debye shield, resulting in short out of electric charge on the comet. Since we are at solar minimum there’s less chance of that happening. If a CME blasts the comet on its way out then it reduces the chance of bright comet.
Also, implicitly with this post I’m asserting Ison hasn’t disintegrated to dust as some people wonder with this 2nd ‘lights out’ occurrence. Just takes time for new ion jets to emerge and power up.
Note that Leif denounces my every word on WUWT comments and says comets are fully understood, but he himself was rather quiet when Ison seemed to go poof, while I raised a flag straight after I read the article, saying I didn’t think it had been destroyed.
Now I’ve just beaten him to predictions of Ison’s Earth flyby.
What say ye, Leif? The ‘not even wrong’ label you erroneously throw at me applies when no predictions are made, but then excuses are made post-event. So it was appropriate to mention it, but you applied it to the wrong commentator.
Same again this time round? I make prediction and you don’t? I’ve waited till the old ion jets fizzle out b4 making this prediction.
If I was you, I’d play safe and cook up conventional reasons why everything I’ve just predicted is going to happen. Straying away from the EU prediction could leave you being proved wrong. And unlike me, seems you are afraid of being wrong.
And what else can these cometary tails (or tales) tell us?
About the ubiquity of the “charge exchange” process, producing XRays in the universe.
Solar system X-rays from charge exchange processes
K. Dennerl1,, C.M. Lisse2, A. Bhardwaj3, D.J.Christian4, S.J. Wolk5, D. Bodewits6, T.H. Zurbuchen7,
M. Combi7, and S. Lepri7
http://deepblue.lib.umich.edu/bitstream/handle/2027.42/91180/324_ftp.pdf?sequence=1
…2 Charge exchange in comets
Comets play a central role in the investigation of the charge
exchange process, because their X-ray emission is the direct result
of this interaction between highly charged heavy
ions in the solar wind and cometary neutrals. As the gas
around comets is cold, there is essentially no thermal X-ray
emission, and as it is not subject to a strong electric or magnetic
field, X-ray emission by energetic electrons is negligible.
Furthermore, the cometary nucleus is so small, and the
gas and the embedded dust grains are so diluted, that there
are not enough targets for solar X-ray scattering to become
important. This has the exciting consequence that the Xray
emission of comets is essentially pure charge exchange
emission (Fig. 1).
Thus, comets represent perhaps the best laboratory
for studying the physics of charge exchange. With highly
charged heavy ions streaming into the cold, tenuous
cometary gas, nature is providing a clean experimental setup
and a textbook example of a system which is far away
from thermal equilibrium….
edit : “solar minimum” I mean the 85-100 year gliessburg cycle minimum, not the 9-13year schwabe cycle. SC24 is very weak as most of us know here
meemoe_uk says:
December 1, 2013 at 12:54 pm
Can you please direct me to your meemoe_uk.org page where you have linked all your published papers on the subject, the papers that explain in detail the math and science from which you draw your conclusions. I would be interested in learning more.
meemoe_uk says:
December 1, 2013 at 12:54 pm
In theory its not a rod. But a tail can approximate a rod if the matter is ejected from the nucleus with high enough velocity to make other factors negligible.
The comet moves at high speed: 300 km/sec so other factors are not negligible.
Note that Leif denounces my every word on WUWT comments and says comets are fully understood, but he himself was rather quiet when Ison seemed to go poof, while I raised a flag straight after I read the article, saying I didn’t think it had been destroyed.
Didn’t I say that ISON could not have been tidally disrupted… This was clear long before perihelion.
What say ye, Leif?
I say you have not said anything worthwhile.
I’ve waited till the old ion jets fizzle out b4 making this prediction.
Predicting after the fact?
Straying away from the EU prediction could leave you being proved wrong.
It is a hallmark of science to be wrong at times, that is what makes it self-correcting science. EU is claimed to be never wrong, so is not science. Tell me, when was the last time EU was wrong? Or better, how many times do you know where EU was wrong?
Ya know if we weren’t so fixated on trying to “get” Dr. S., maybe we might finally “get” what he is trying to tell us.
Maybe or maybe not?
toss coin maybe
toss coin again maybe not
Oh well shoot for sometimes we’ll get it. maybe
Leif wrote Predicting after the fact?
No, my predictions above are for the return Earth fly by of Ison. I wasn’t ambiguous about that.
Your decoys and obfuscations are getting more obvious ( and desperate) every post.
meemoe_uk says:
December 1, 2013 at 2:01 pm
No, my predictions above are for the return Earth fly by of Ison. I wasn’t ambiguous about that.
Perhaps only obscure. What is that prediction again? Hard to find one’s way through your verbiage…
Predictably, you went quiet on:
It is a hallmark of science to be wrong at times, that is what makes it self-correcting science. EU is claimed to be never wrong, so is not science. Tell me, when was the last time EU was wrong? Or better, how many times do you know where EU was wrong?
Can you please direct me to your meemoe_uk.org
sure tom
its here
http://wattsupwiththat.com/2013/11/30/zombie-comet-ison-dies-again/#comment-1489008
xD
The comet moves at high speed: 300 km/sec so other factors are not negligible.
370km/s max.
During perhelion yes, the tail was curved.12 hours after perhilion, the comet velocity had significantly dropped and the tail straightened and remained straight.
Observation trumps theory, the observation was the ion tail was set straight and off angle for 2 days.
Tell me, when was the last time EU was wrong?
The last big blunder was when Alfven hypothesized a new type of magnetic field – a ‘frozen’ magnetic field. It was the only bit of his work he would have like to have been discarded, but it’s ended up as one of the very few bits that conventional astronomy has embraced.
@sparks
Try starting…
TAKE 5
A comet is a charged body….
lsvalgaard says:
December 1, 2013 at 1:14 pm
The comet moves at high speed: 300 km/sec so other factors are not negligible.
Didn’t I say that ISON could not have been tidally disrupted… This was clear long before perihelion
——-
Thanks Dr. S.,
One of the most exciting movies on ISON for me, was seeing the solar wind passing over it and making its tail wiggle. lol
From spaceweather.com time machine.
http://www.spaceweather.com/archive.php?day=24&month=11&year=2013&view=view
The movie link below
http://science.nasa.gov/media/medialibrary/2013/11/24/ison_encke_nov19_22.gif
..””In the movie, which spans a two+ day period from Nov. 20 to Nov. 22, the sun is to the right, off-screen. “The dark ‘clouds’ coming from that direction are density enhancements in the solar wind, and these are what are causing the ripples you see in the comet tails,” explains Karl Battams of NASA’s Comet ISON Observing Campaign..””
meemoe_uk says:
December 1, 2013 at 2:15 pm
During perihelion yes, the tail was curved.12 hours after perhilion, the comet velocity had significantly dropped and the tail straightened and remained straight. Observation trumps theory, the observation was the ion tail was set straight and off angle for 2 days.
Misunderstood observations do not trump anything. People have looked at the orientation [corrected for projection] on hundreds of observations, e.g. as reported here http://www.leif.org/EOS/1968-Brandt-Comet-Tails.pdf and found that there true orientation conforms to theory, including the 4 degree aberration.
The last big blunder was when Alfven hypothesized a new type of magnetic field – a ‘frozen’ magnetic field.
Observations [in space and in the laboratory] show that Alfven was correct about that after all. Besides, he suggested the frozen-in magnetic field in the 1940s, long before there was any EU theory. Are you saying that this was the only blunder? Are there none other?
Tom in Florida says:
December 1, 2013 at 1:02 pm
Can you please direct me to your meemoe_uk.org page
Seriously I do have my own science website, but it’s not an EU or astronomy site.
If you want more EU theory try google thunderbolts. ( I’m not going to link, the WUWT mods don’t like EU )
meemoe_uk says:
December 1, 2013 at 2:32 pm
If you want more EU theory try google thunderbolts.
or http://www.crankastronomy.org/anomalies/ElectricSky_20080322.pdf
I find it very funny that the “Science” Channel (aka all AGW all the time) is running a special on “Super Comet ISON” this Saturday. Based on all that’s happened, not only was that ballsy programming decision which had to have been made several weeks ago, but due to the comet’s alleged and likely death it seems quite a poor decision. Perhaps Morgan Freeman narrating it might salvage the show. /sarc
meemoe_uk says: During perhelion yes, the tail was curved
Oh, and I’ve left something hanging. While I agree with you about curved tails during perihelion. I disagree as to why the tail is curved. It curves cos the comet rotates with its orbit, and so do the ion jets that are fixed in position and direction on the surface of the comet.
Conventional theory is flawed. This explains why I can use a single simple geometric principle when analysing Ison ( a line radially directed to a point, points to the point from any perspective ) to disprove convention, but you have to invoke the max planck institute with their dozens of scientists and super computer, or 20 page academic papers with walls of text. Because its heavy work trying to fudge up knowledge to fit in with a crank theory.
4 degrees aberration sounds sensible. Just another 76degrees to go and I’ll swap over to conventional astronomy.
Do we know if the angle it’s coming back from the Sun has changed? If it’s any lower that’s a problem.