Comet ISON appears to be toast – goes "poof" in video, then comes back to life

McCoy_ISON_Its_undead_JimNote: See updates below for the ISON ISOFF ISON nature of this comet that has everybody guessing. Picture at right also updated to reflect the new “zombie” status of this comet.

Looks like ISON has disintegrated during its turn around the sun. Given the radiation (estimated temperature 5,000F/2,760C – hot enough to vaporize rock), solar wind, and the tidal-forces (even though smallish, thanks Gavin) associated with its proximity and nearly 800,000 mph speed around the turn about that time, I’m not surprised. Watch the second video below where it goes “poof” (h/t to reader “David”)

NASA’s spaceweather.com reports:

Comet ISON is making its closest approach to the sun, and evidence is mounting that the nucleus of the comet has disintegrated. Watch the head of the comet fade dramatically as it approaches the sun in this SOHO coronagraph movie:

(may take a minute to load)

sundiver_anim3[1]

The movie spans a day and a half period from Nov. 27th (01:41 UT) to 28th (15:22 UT). In the early hours of the 27th, Comet ISON brightens dramatically, saturating the pixels in the digital camera of the SOHO’s coronagraph. By mid-day on the 28th, however, the comet’s head appears to fade. This is a sign that the nucleus has likely fallen apart. That would make ISON a headless comet–more appropriate for Halloween than Thanksgiving.

Researchers working with the Solar Dynamics Observatory report that they are seeing nothing along the track that ISON was expected to follow through the sun’s atmosphere.

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UPDATE: Watch it go “poof” here:

ISON_poof

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UPDATE2: NASA JPL Insider Amy Mainzer tweets some last minute hope that ISON may be “undead”

http://twitter.com/AmyMainzer/status/406179229487742976

A zombie comet, how cool is that?

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UPDATE3: Now it seems back again, but looking entirely different than before. A number of astronomers indicate they don’t know what is left of it, maybe a chunk, maybe a smooshed drawn out nucleus or something else. Image from SOHO’s coronagraph:

SOHO_ISON_post_perihelion

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Alvin
November 28, 2013 12:27 pm

More snowball than rock.

November 28, 2013 12:35 pm

The big CME didn’t help much ;>)

Pamela Gray
November 28, 2013 12:35 pm

That is cool. Pacman eats the dot.

November 28, 2013 12:35 pm

The g forces will not cause disintegration but the tidal forces might.
REPLY: Yes also noted on twitter by Gavin. I’ve corrected it. Some stretching of the nucleus along the path due to tidal force may have aided in disintegration. – Anthony

PaulH
November 28, 2013 12:36 pm

This reminds me of what happened to the theory of CAGW right after Climategate.
;->

Paul
November 28, 2013 12:37 pm

Must have picked up some of dat der carboon daoxade from Earth and heatud urp tooo much an exploded an’ all.

u.k.(us)
November 28, 2013 12:42 pm

I’m sure it is impossible for such a small object to create a “CME”, but it sure looks like it did ??

November 28, 2013 12:42 pm

G forces?
ISON is in free fall. Does not feel a thing\
REPLY: I meant tidal forces, and corrected the text before you wrote this comment – A

Paul Westhaver
November 28, 2013 12:43 pm

The second gif is better. The accidental looping of the blue images with the preceding mass ejection location makes an ambiguous GIF. Red is better or add a few frames to the blue gif at the beginning and at the end.

Paul
November 28, 2013 12:45 pm

Comet Icarus.

November 28, 2013 12:55 pm

Tidal forces are not “associated” with speed only with distance and size of comet
REPLY: Yes, trying to write all this in-between family duties today, text was updated just about time you commented. Originally, I was thinking about how gravity interaction with Jupiter busted up comet Shoemaker-Levy9 – A

hunter
November 28, 2013 12:59 pm

It was a poof that in the red video seems to be dramatically explosive. But at > 1,000,000 kph the kinetic energy would be….. astronomical.

Doug Huffman
November 28, 2013 1:00 pm

Darn.

RangerRick
November 28, 2013 1:02 pm

I sure ISON’s destruction was George Bush’s fault.

November 28, 2013 1:07 pm

Oh, well, only 48 years for Halley.

Gijs
November 28, 2013 1:09 pm

The CME isn’t the reaction of the nearby coming comet, it’s at the beginning of the sequence, at the startpoint of the movie where the comet is coming into picture at right. Butt still a magnificent sight!

November 28, 2013 1:14 pm

I’m not convinced that it has been destroyed yet, I’ve seen comets behave like that in SOHO images only to see them reappear sometime after aphelion, its rare but it can and does happen.

Snotrocket
November 28, 2013 1:14 pm

Snowball warming!!!

November 28, 2013 1:16 pm

While you are at it, remove the speed bit. Tidal forces has nothing to do with speed.
REPLY: Leif, the speed stays. It’s relevant to the report. Note the word “proximity” Speed of comet into solar wind will add shear force and ablation -A

Editor
November 28, 2013 1:17 pm

Bwaa haa haa. So are all the Nibiru-nuts going to take down their Youtube videos? Search query http://www.youtube.com/results?search_query=niniru+ison&sm=3 for some major giggles. How long before CAGW goes poof?

meemoe_uk
November 28, 2013 1:18 pm

A comet’s lights going out doesn’t guarantee its been destroyed. It has arc discharged its electric potential, so it no longer has its ionic glow. It may have survived the trauma of the arc discharge, and is now the same voltage as it environment.
On the other hand it may have been destroyed.
Too early to tell, but at this moment I’m guessing it hasn’t been destroyed

Bruce Cobb
November 28, 2013 1:19 pm

It will be surely mist.

byz
November 28, 2013 1:24 pm

The CME might have pulled off the tail (it’s happened before) and the comet seems to disappear where the CME has exited from.
If the nucleus survived then it may take time to form a new tail.
Highly likely it disintegrated, however a two mile nucleus with no tail will be very hard to spot!

November 28, 2013 1:25 pm

Anthony Check this out. What do you make of it?
http://sohowww.nascom.nasa.gov/data/realtime/c2/512/latest.jpg
REPLY: Almost looks like the comet skipped off the photosphere, but that may be solar wind transport of comet ejecta – Anthony

meltemian
November 28, 2013 1:35 pm

Now I don’t know whether to get up early to look or not!!

Bill Illis
November 28, 2013 1:37 pm

There is definitely a track now on Lasco C2.
It does appear as those the solar wind wind or magnetic field adjusted its orbit slightly from the extreme slighshot it was supposed to have.
It must be a very small object now though.
http://s7.postimg.org/5ioq6m6ej/20131128_2024_c2_512.jpg

November 28, 2013 1:40 pm

Looks like some rock and dust did survive, not much to look at, though.
https://twitter.com/AmyMainzer/status/406171212826431489/photo/1

meemoe_uk
November 28, 2013 1:45 pm

current SOHO webpage is displaying a photo taken 12 minutes later than the one posted by Bill Illis
http://sohowww.nascom.nasa.gov/data/realtime/c2/512/
taken at 20:36 GMT
looks like ISON is still substantially there

November 28, 2013 1:46 pm

At least mankind can’t be blamed for this one.
Great shots, by the way. It’s terrific to be able to watch something like this. Oh, and Happy Thanksgiving to all. 🙂

meemoe_uk
November 28, 2013 1:50 pm

If ISON had substantially exploded\fragmented we would have seen the fragments already.
It’s now looks like ISON survived the arc discharge without serious damage.

November 28, 2013 1:50 pm

SOHO now confirms, ISON dead. Confirms that there is a “debris arc” but that is all.

November 28, 2013 1:52 pm

ESA: dead Canadian Space Agency: Dead

High Treason
November 28, 2013 1:55 pm

Explains why, when I had the first clear morning in ages and up early enough there was no comet to be seen.

J. Sperry
November 28, 2013 1:57 pm

Now I can catch up on all the sleep I lost waking up early to see this dud. Never caught a glimpse of it without optical aid.

Paul Westhaver
November 28, 2013 2:13 pm

any debris coming our way… should we inform Bill Nye the Science Liar?

meemoe_uk
November 28, 2013 2:17 pm

the continuing trail is far too coherent \ concentrated to be a debris arc. It’s a single object creating the trail. When deciding if its a fragment or the whole comet, consider this : if its a small fragment making the significant trail, then why don’t all the other fragments make significant trails? Based on that I’d say its the whole comet.
latest pic at 21:36GMT from nasa inside Amy Mainzer
https://twitter.com/AmyMainzer/status/406179229487742976/photo/1/large

November 28, 2013 2:19 pm

There looks to be a distinct cometary nucleus emerging, the solar wind may have blown much of the tail away from the nucleus, if enough of the comet has survived the tail should increase in size again.

oakwood
November 28, 2013 2:23 pm

Oh, that would be a pity.I’m watching right now BBC’s Horizon programme about the comet – getting excited about the potential sky display (which I had recorded from a few days ago).

November 28, 2013 2:27 pm

meemoe_uk says:
November 28, 2013 at 2:17 pm
“if its a small fragment making the significant trail, then why don’t all the other fragments make significant trails? Based on that I’d say its the whole comet.”
Exactly, that’s a good point! Why are we not seeing two or more trails if it broke into two or more fragments?

Editor
November 28, 2013 2:28 pm

hunter says:
November 28, 2013 at 12:59 pm
> It was a poof that in the red video seems to be dramatically explosive. But at > 1,000,000 kph the kinetic energy would be….. astronomical.
The kinetic energy would have been significant if it ran into a brick wall. Solar wind doesn’t count. It went from dirty snowball to cloud of gas and dust – with much of that KE along with it.

meemoe_uk
November 28, 2013 2:34 pm

lol, the news reports coming out now are funny.
Australia business insider describes it as ” unbreaking news ” ! – Ison still alive
http://www.businessinsider.com.au/comet-ison-is-dead-long-live-comet-ison-2013-11

byz
November 28, 2013 2:34 pm

looks like the CME did strip the tail after all 🙂
The CME can strip the tail as it is ionised and the CME is magnetic energy.
Will be interesting to see if the tail grows again and if it’s orbit changed 😀

Txomin
November 28, 2013 2:44 pm

Great stuff. Thanks again for posting it.

Leo G
November 28, 2013 2:48 pm

ISNO?

TRM
November 28, 2013 2:52 pm

Too bad. It was supposed to be a good show. Next.

meemoe_uk
November 28, 2013 2:57 pm

“striping the tail” is a bad analogy.
The comet loses its tail because the tail is plasma in glow mode due to a high voltage on the surface of the comet. The CME is a plume of ions, i.e. highly conductive plasma. When ISON flew into the CME it earthed its voltage ( or Suned it ), so the glowing stopped.
Why its now starting to glow again is interesting. It’s gaining voltage relative to its surroundings. Either the voltage it got from the sun is already significantly different to its current environment or charge is leaking from a reservoir in its core to its surface. Fun speculation.

Fernando
November 28, 2013 3:01 pm

Anthony, I sincerely hope you are wonderful team of moderators.
Understand this comment as an “explosion” of indignation.
==========================
A famous Comet ISON prophecy was made by Nostradamus. And there are connections between the close approach of Comet ISON to the Sun and the Mayan Haab calendar. Mundane astrology also connects the date of Comet ISON’s close approach in November, 2013, with major global events and possible catastrophes.
http://www.mayancalendarusersguide.com/Comets-Asteroids-Prophecy-Maya/comet-ison-prophecy.html
===========================
‘of the century’ = Hiayan
===========================
I do not know if it makes sense in English:
centurie
century
===========================
I think that model adjustment is required
http://i1195.photobucket.com/albums/aa391/MAFILI/iz2912_zps8a80300e.png
[always remember to use the /sarc tag -mod]

November 28, 2013 3:05 pm

lasco-www.nrl.navy.mil/java/lastC2.html

Dubya G
November 28, 2013 3:09 pm

I don’t think even Obamacare will help ISON much now. It appears to have gone the same way as the website.

petermue
November 28, 2013 3:11 pm

What is the bright spot in the 2nd video at the left side?

phlogiston
November 28, 2013 3:12 pm

Comets’ icy cores are typically not dense and compact but only a loose assemblage without any mechanical strength. So even a weak tidal force could pull it apart to be scattered by solar wind.

Don Worley
November 28, 2013 3:15 pm

If the exhaust of gases and interaction with the solar wind caused a very rapid spin, then wouldn’t g forces be an appropriate term? Negative g forces could rip it apart.

Kev-in-Uk
November 28, 2013 3:17 pm

phlogiston says:
November 28, 2013 at 3:12 pm
I’m struggling to grasp that concept. Tidal (gravitational) forces will essentially act equally on all the parts of the relatively small body of the comet so why should it break up? Obviously, if it is mostly ice and rock, we could understand ‘melting’ aiding in said break up?

meemoe_uk
November 28, 2013 3:20 pm

Lastest pic 22:24 GMT
http://sohowww.nascom.nasa.gov/data/realtime/c2/512/
looks like a healthy comet to me

Kev-in-Uk
November 28, 2013 3:28 pm

meemoe_uk says:
November 28, 2013 at 3:20 pm
so where is the nucleus/head??? It looks to me more like the head has disintegrated and kinda spread out a bit? (well, a lot actually!)

Kev-in-Uk
November 28, 2013 3:37 pm

BTW, does anyone else see the size of the comet head appear to reduce during solar approach in the blue gif sequence above? Not sure if it’s a scale issue or if it was actually being ‘burnt’ away? Tail gets more intense too (but is that due to solar energy effects?) ?

November 28, 2013 3:46 pm

Ah, the latest SOHO image distinctly shows something coming around the other side…
http://soho.esac.esa.int/data/realtime/c3/512/latest.jpg

meemoe_uk
November 28, 2013 3:46 pm

@kev
its at the front of the cometary blur just as always, but its not glowing as much as before the discharge event.
As i write this Ison will be moving out of SOHO LASCO C2 standard camera view. NASA should get 1 more shot in. Just waiting for it now

George McFly.....I'm your density
November 28, 2013 3:47 pm

The quarterback is toast…..

November 28, 2013 3:48 pm

There is a debris trail. Note that the “tail” follows the trajectory of the comet. It is not a comet tail which would point away from the Sun.

Kev-in-Uk
November 28, 2013 3:54 pm

meemoe_uk says:
November 28, 2013 at 3:46 pm
Perhaps – but I’m not convinced! and the last image I’ve seen (22.54) shows a less bright ‘gap’ between the apex of where the head should be and the brighter section of tail. I’m thinking it has melted/broken up and the small bright tail is the remnants. If the tail fades further would that suggest it has no real head left (perhaps a small amount of rock?)?
will have to catch up with events tomorrow now – bedtime here, been a long day – cheers!

Kev-in-Uk
November 28, 2013 3:55 pm

crosspatch says:
November 28, 2013 at 3:48 pm
Yeah, I thought that too…….

pat
November 28, 2013 3:56 pm

28 Nov: UK Telegraph: Julian Ryall: Japanese firm plans 250 mile-wide solar panel belt around Moon
Tokyo-based Shimizu Corp. wants to lay a belt of solar panels 250 miles wide around the equator of our orbiting neighbour and then relay the constant supply of energy to “receiving stations” on Earth by way of lasers or microwave transmission.
The “Luna Ring” that is being proposed would be capable of sending 13,000 terawatts of power to Earth. Throughout the whole of 2011, it points out, the United States only generated 4,100 terawatts of power…
Once completed, the belt would stretch 6,800 miles around the equator and ensure constant exposure to the sun – without the interference of cloud cover – and an equally constant transfer of energy to the Earth.
Shimizu believes that “virtually inexhaustible, non-polluting solar energy is the ultimate source of green energy”.
http://www.telegraph.co.uk/news/worldnews/asia/japan/10480950/Japanese-firm-plans-250-mile-wide-solar-panel-belt-around-Moon.html

November 28, 2013 3:59 pm

So how many solar atomic bombs does it take to kill a comet?

meemoe_uk
November 28, 2013 4:04 pm

[i]>There is a debris trail. Note that the “tail” follows the trajectory of the comet. It is not a comet tail which would point away from the Sun.[/i]
The ‘debris trail’ was trailing in the trajectory b4 the discharge event. So a trailing tail now doesn’t indicate fragmentation.
Healthy comet tails can be in comet’s trajectory path, or away or towards the sun.
Comets never melt because they are not made of ice. The deep impact mission of last decade gave strong evidence that comets are rocks, i.e. an asteroid with a highly elliptical orbit.

son of mulder
November 28, 2013 4:08 pm

It’s simply hiding with all the missing heat.

November 28, 2013 4:09 pm

It’s alive Jim, but not as we know it.

meemoe_uk
November 28, 2013 4:11 pm

ok the latest pic is up at soho ( linked above )
Amy Mainzer has stopped tweeting but John Maclean of Norman Lockyer Observatory is still active, he’s done a vid of the last few shots
https://twitter.com/search?q=john%20maclean&src=typd
his said in his last tweet he thinks its just dust

meemoe_uk
November 28, 2013 4:25 pm

we already know the main body isn’t dust because you can see a molecular gas\vapour being blown off in the 23:24GMT pic by the solar wind to the left side of comet. That stuff is doing what dust would do. The main body is not being blown away by the solar wind.
And since we only got 1 visible fragment after the discharge event the only assertion you can make is Ison got fragmented but all the fragments stayed together. That is very unlikely.
We can already be >99% certain its still all in one piece.
Shame we didn’t get close up shots b4 it got zapped. There will be a new, and likely big, discharge crater on its surface.

Bill Illis
November 28, 2013 4:27 pm

Well, something made it through.
From Lasco C2.
http://s29.postimg.org/qg5kdfg3b/20131128_2324_c2_512.jpg
And now showing up on Lasco C3.
http://s27.postimg.org/5xi0ucl5v/20131128_2318_c3_512.jpg
The predicted path versus the current path of “whatever it is” appears to be shifted slightly – compare to C2 above.
http://s30.postimg.org/7dgoa0htt/pascal_perihelion.jpg
Note I’m putting up saved images because there has been a lot of traffic to the SOHO websites and it is not worthwhile putting up direct links.
But the SDO satellite process was supposed to capture some of this comet and they would have been spectacular movies with pictures captured every few seconds. Nothing at all showed up however. For example, if SDO could have captured the comet’s path in this video (one of 12 different possible capture scenarios), it would have been amazing. Nothing however.
http://cometison.gsfc.nasa.gov/index/kiosk/dataset/two_0171

November 28, 2013 4:38 pm

Apparently, Comet 2012 S1 (ISON) broke up at 17:36 UT, Nov. 28 ’13, just before perihelion.
See SOHO coronagraph photo at 17:36 UT, Nov. 28 ’13, at http://sohowww.nascom.nasa.gov//data/REPROCESSING/Completed/2013/c2/20131128/20131128_1736_c2_512.jpg
Also see SOHO coronagraph movie (November 28th ’13, 11:36 to 20:13 UT) (NASA – SpaceWeather.com), at http://spaceweather.com/images2013/28nov13/rip_anim2.gif?PHPSESSID=vfmvc3o1i9o24fdcjemma7rn55

jim2
November 28, 2013 4:45 pm

Something made it through. You can make your own slide show here:
http://stereo-ssc.nascom.nasa.gov/cgi-bin/images

meemoe_uk
November 28, 2013 4:46 pm

John Maclean’s latest vid, most up to date vid at this moment

includes images up to 23:48 UT

Fernando
November 28, 2013 4:50 pm

jim2
November 28, 2013 4:53 pm

It’s ion tail is visible again.

Adam
November 28, 2013 4:58 pm

It is not a comet. It is a space ship flying close to the sun to use the gravity to slingshot it back in time. They are probably going to save a whale or something like that.

meemoe_uk
November 28, 2013 5:07 pm

its moved out from under the LASCO 3 sun shield and into view on the 23:30GMT shot
its apparently brighter than any of the solar\coronal plasma in view.
Looking fine
http://sohowww.nascom.nasa.gov/data/realtime/c3/512/
I’ll accept my noble prize on 3pm on Friday after I’ve collected my dole check. Just beaten the all the world’s professional astronomers to the correct conclusion on the non-fragmentation of Ison in its solar encounter.

KarlB
November 28, 2013 5:23 pm
November 28, 2013 5:24 pm
jim2
November 28, 2013 5:27 pm

On COR2, at 21:39:24 you see it brighten. Then as the frames move to 22:24:24, you see it break into a large and a small piece.

DirkH
November 28, 2013 5:28 pm

VERY nice, meemoe.

November 28, 2013 5:36 pm

It’s not dead
It’s resting.
It’s pining for the fjords.

meemoe_uk
November 28, 2013 5:36 pm

@jim2 haven’t seen it or heard news of it. pls supply a link

November 28, 2013 5:43 pm

I have been watching this all day and have to agree with meemoe_uk: there is a comet now travelling away from the Sun. Unless there was a second comet nobody had mentioned before it appears that rumours of ISON’s demise have been greatly exaggerated.

November 28, 2013 5:51 pm

Is it possible y’all have mis-interpreted how the sun’s lighting works with the nucleus and the tail?
A forward-scattering of the light (as when the comet is closer to us) versus back-scatter (when the comet is further away, and going behind sun) kind of thing?
.

meemoe_uk
November 28, 2013 5:55 pm

yeah, the tide of opinion is turning fast …
i’ve been browsing the yahoo comet news groups..
http://groups.yahoo.com/neo/groups/comets-ml/conversations/messages
“Golly! So the comet is not dead yet……I have been looking at the latest SOHO images and the comet appears to be quite alive and well. ” –
Dr. P. Clay Sherrod
Arkansas Sky Observatories 12:38am GMT 29 Nov 2013

meemoe_uk
November 28, 2013 6:15 pm

John Maclean has just switched his opinion and told the Mass Media that Ison is alive and well.
https://twitter.com/AstroExeter
Don’t know if he’s their #1 space correspondent, but they’ve listened to him b4.

Geoff Withnell
November 28, 2013 6:25 pm

Tidal forces arise because the part of the comet closer to the sun experiences more gravitation pull than the part further away. The amount of tidal force generated depends on the ratio of the width of the object to the distance to the other object, so as the comet comes cloaer to the sun, the tidal force increases.
phlogiston says:
November 28, 2013 at 3:12 pm
I’m struggling to grasp that concept. Tidal (gravitational) forces will essentially act equally on all the parts of the relatively small body of the comet so why should it break up? Obviously, if it is mostly ice and rock, we could understand ‘melting’ aiding in said break up?

jim2
November 28, 2013 6:34 pm

meemoe_uk says:
November 28, 2013 at 5:36 pm
meemoe_uk – go here and select the last 25 frames, highest resolution and the COR2 satellite. As the comet just clears the Sun, it brightens, then a small piece appears to separate and move to the right of the main body.
http://stereo-ssc.nascom.nasa.gov/cgi-bin/images

meemoe_uk
November 28, 2013 6:47 pm

ok i looked and i didn’t see any fragment come off. It’s just the plasma tail blowing about.

meemoe_uk
November 28, 2013 6:53 pm

I like Phil Platt’s blog post, after a lot of hype about it being destroyed he posts this
http://www.slate.com/blogs/bad_astronomy.html
UPDATE 2 (Nov. 29 at 02:30 UTC):….At this point, I refuse to make any further conclusions about this comet; it seems eager to confuse. I’ve been hearing from comet specialists who are just as baffled… which is fantastic! If we knew what was going on, there’d be nothing more to learn
It didn’t confuse me, and I’m not a comet specialist.

Steve R
November 28, 2013 7:05 pm

Seems it really never had much more than a snowballs chance in hell.

November 28, 2013 7:32 pm

Don’t normally read Science blogs but stylistically it’s impeccably written (too many adverbs). Do visit my blog if you have the chance, it’s about video games (http://theinkandpen.wordpress.com/)

Tom J
November 28, 2013 7:47 pm

A.D. Everard
November 28, 2013 at 1:46 pm
‘At least mankind can’t be blamed for this one.’
Don’t bet on it.

November 28, 2013 7:52 pm

Geoff Withnell says:
November 28, 2013 at 6:25 pm
I’m struggling to grasp that concept. Tidal (gravitational) forces will essentially act equally on all the parts of the relatively small body of the comet so why should it break up?
You are right about that. The tidal forces on such a small body are not strong enough to break it up and the notion [as presented in the post] that the forces are associated with or have anything to do with the speed with which the comet rounds the Sun in a free fall is totally false. It should be corrected.
REPLY: Leif I’m not making any claim about speed and tidal forces being connected. Speed does have an effect though, related to the comet impacting areas of denser particle emissions coming from the sun. Slamming into a particle stream coming at you 90 degrees from your path of travel at a path speed of 800,000 mph isn’t anything to ignore, especially for something as tenuous as a snowball comet. There’s going to be ablation. You can see this in the Stereo video above.
And tidal forces do have an effect on comets, as explained here by this Cornell Q and A on Comet Shoemaker Levy 9 and how it reacted to tidal forces of Jupiter. Loosely packed snowballs behave differently under such conditions.
From: http://curious.astro.cornell.edu/question.php?number=217

Now, you are rightly puzzled about the cohesion of the comet.You or I would be ripped apart by the tidal force the Earthexerts on us, pulling harder on our feet and less hard on our heads, except that we are not held together by our own gravity –we have strength, cohesion. Similarly, if we pack together a snowball, we can see that it isn’t pulled apart by tides, either. However, comets aren’t packed together. They are quite tenuous in their construction. They form as ice and other substances slowly freeze onto them out of the vacuum of space on to bits of dust, and then they are subject to bombardent by other comets, as well as being continually pecked at by micrometeorites, the size of grains of sand. The comet is made of lacy pieces of ice of various sizes, held together only by the gravity of its own tiny mass.
That gravity holds it together pretty well, too — unless it passes too close to a behemoth like Jupiter, where the tidal force stretching it apart will be greater than the gravity holding it together. Remember that Shoemaker-Levy 9 was the first comet observed with this pearl-string structure. Most comets don’t pass so close to a planet without running into it!

The comment about tidal forces stays, so does speed.
Anthony

Carla
November 28, 2013 8:09 pm
Carla
November 28, 2013 8:15 pm

Are these sun escaping comets going to become more frequent?
Lovejoy
http://sungrazer.nrl.navy.mil/index.php?p=images/lovejoy/EUVI_B_lovejoy.gif

November 28, 2013 8:20 pm

Hmmm,..why haven’t the experts seen this for what it really is,…a starship a la ‘Destiny’, which is merely dropping into the Sun for a recharge…
:).

meemoe_uk
November 28, 2013 8:22 pm

as long as the solar cycle is weak, yes. Comets are more likely to explode during solar maximum

November 28, 2013 8:24 pm

meemoe_uk says:
November 28, 2013 at 8:22 pm
as long as the solar cycle is weak, yes. Comets are more likely to explode during solar maximum
Where is the observational data supporting this?

Bob Diaz
November 28, 2013 8:48 pm

If the comet is really gone, I’m sure Al Gore will blame it on increased levels of CO2 on Earth. ;-))

meemoe_uk
November 28, 2013 8:51 pm

@leif
oh it’ll be all scattered around in the comet observation archives. Doubt it’s been compiled into a coherent report. Could do with some comet dude with all the data at his fingers to post a time line of exploding comets.
Until then its just something us EU guys know and gravity people deny.
Where is the data that falsifies this?

November 28, 2013 8:59 pm

meemoe_uk says:
November 28, 2013 at 8:51 pm
Doubt it’s been compiled into a coherent report. Could do with some comet dude with all the data at his fingers to post a time line of exploding comets.
so you have no data, just speculation.
Until then its just something us EU guys know and gravity people deny.
Where is the data that falsifies this?

You cannot know anything without data, and EU has been falsified countless times.

Editor
November 28, 2013 9:41 pm

Leif Svalgaard says:
November 28, 2013 at 7:52 pm

The tidal forces on such a small body are not strong enough to break it up and the notion [as presented in the post] that the forces are associated with or have anything to do with the speed with which the comet rounds the Sun in a free fall is totally false. It should be corrected.

So why did it break up? Heating evaporating subsurface ice and blowing the comet apart?
At least one comet is believed to have broken up without significant solar heating, comet Shoemaker-Levy 9.
It broke apart during a pass by Jupiter only 1.3 Jupiter radii away and broke into 21 pieces (or clumps – the comet apparently was very fragile). Then they impacted Jupiter in a event never witnessed before. Better Jupiter than Earth!
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=2003ASPC..291..415W&db_key=AST
https://archive.org/details/SVS-85 (a graphical simulation of a “rubble pile” SL-9.)

November 28, 2013 9:44 pm

The last few seconds of Fernando’s video clip above seems to show that the comet has survived. The imagery suggests that it is at least partially intact and following its intended trajectory around the Sun’s corona.
http://wattsupwiththat.com/2013/11/28/comet-ison-appears-to-be-toast/#comment-1486797
The total mass of the corona is vanishingly small: 3×10¹⁴kg. In comparison, only 1/10 of the mass of Mount Everest: 3×10¹⁵kg! And only 1/10000th the mass of Earth’s atmosphere: 5×10¹⁸kg.
So there’s not much friction there to cause it to disintegrate or steal its kinetic energy. Yes, the temperature of the corona is a million degrees. But it’s so tenuous that there would be neglible transfer of that heat to much more massive objects like the comet. Nor did it apparently get (completely) vaporized by the radiation from the photosphere (5800K).
😐

November 28, 2013 9:50 pm

Ric Werme says:
November 28, 2013 at 9:41 pm
Heating evaporating subsurface ice and blowing the comet apart?
Very likely, especially if the comet is a ‘rubble pile’. e.g. http://www.lpl.arizona.edu/~yelle/eprints/Yelle04a.pdf

November 28, 2013 10:15 pm

Leif Svalgaard says:
November 28, 2013 at 7:52 pm
REPLY: Leif I’m not making any claim about speed and tidal forces being connected.
I see, not connected, just associated….

u.k.(us)
November 28, 2013 10:24 pm

lsvalgaard says:
November 28, 2013 at 10:15 pm
Leif Svalgaard says:
November 28, 2013 at 7:52 pm
REPLY: Leif I’m not making any claim about speed and tidal forces being connected.
I see, not connected, just associated….
================
I’ll bet observation trumps on this one.

November 28, 2013 10:58 pm

The comet has survived fully intact, Mr. Watson! Using your basic faculties of observation, you can see the comet plunging toward the sun from over your right shoulder (in the red images) and in front of most of the coronal ejections. Once the comet passes by the sun, it emerges on the backside of all the coronal ejections and is significantly obscured, but considering this fact one can see that the comet has survived virtually unscathed! Elementary, my dear Watson!

November 28, 2013 11:10 pm

What is ISOD’s orientation to us? is it now backlit?
Was it coming toward the sun on the far side of its orbit and past perhelion its proper motion has a component toward Earth?

November 28, 2013 11:35 pm

Java browser ap for ISON.
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=ison;orb=1;cov=0;log=0;cad=0#orb
ISON approached the sun near the ecliptic about with an Earth-Sun-ISOD angle of about 45 deg.
Came under the South pole. Now it is departing well north of the ecliptic and toward us somewhat. Earth-Sun-ISOD angle is still about 45-60 degreees. It is partly backlit, but it is hard to see orientation is the reason for the change in brightness.

Bill Jamison
November 28, 2013 11:41 pm

Comet ISON will forever be known as the zombie comet.
I sure hope it puts on a show in a few days! Man today was a rollercoaster ride of emotions.

November 28, 2013 11:51 pm

Photobucket images of the ISON orbit. Nov. 30, 2013, Earth at far right, Sun at center. See 11:35 pm post.
Normal to Ecliptic ISON rising toward the viewer.
Oblique to Ecliptic, North of Eclipitc Earth on far right moving away from viewer, ISON moving up, right, and away from the viewer.

Cuthbert Shaw
November 29, 2013 1:21 am

To the mods/Anthony, would you mind just time and date stamping updates, not just for this article but when updating is required for others as well? Thanks muchly

meemoe_uk
November 29, 2013 2:04 am

What’s with the ‘its a snowball’ myth?
http://en.wikipedia.org/wiki/File:Tempel_Impactor_150Km.jpg
NASA went to all that effort to photograph a comet up close in 2005 and got hard evidence that they are rocks, not ice.

Bloke down the pub
November 29, 2013 2:19 am

Considering that the msm likes to make a drama out of everything, I’m suprised that there has been no word yet on the potential for the debris from Ison to impact the Earth. Outgassing etc is sure to alter the orbit of any remnants from that which was originally projected.

meemoe_uk
November 29, 2013 2:50 am

At least one comet is believed to have broken up without significant solar heating, comet Shoemaker-Levy 9.
Comets can suddenly flare up and fragment away from the sun or any planet.
So its not heating, or tidal forces that fragment them

Twobob
November 29, 2013 3:13 am

So we have a large hot glowing lump of rock.
Traveling back out from the sun on an altered orbit.
The next few days ARE going to interesting.

meemoe_uk
November 29, 2013 3:19 am

OK, that 2nd jet \ tail on its left side is now as big as its trailing tail

French_Atkins
November 29, 2013 3:29 am

As a fellow “astronomo-sceptic”, I totally agree with what meemoe_uk has been saying about an electric interpretation of what is unfolding before us. It will be highly amusing to see the professional astronomers (including “bad” ones…) groggy on the ropes again, as they always are where comets are concerned. As usual, they’ll be groping blindly around in the dark again for the latest ad hoc “explanation” for what is just another in a long line of huge surprises for them (as they did, in particular, with the observational data from the Deep Impact and Stardust missions).
The case is clear: Ison, like the four comet nuclei we have so far actually managed to image from pretty close-up, is not a “dirty iceball” but a big lump of solid rock, which displayed intense discharge phenomena with build-up of increasing voltage difference as it moved rapidly towards the positively charged sun. It seems, as meemoe_uk suggests, that “when ISON flew into the CME it earthed its voltage ( or Suned it ), so the glowing stopped”, a phenomenon which is totally in accordance with the expectations of EU theory but totally inexplicable by mainstream, gravity-only Big Bang theory.
Now that this big lump of rock has emerged on the other side with a fantastic gravity assist and a speed still in excess of 600,000 mph, the charge difference will once again increase very rapidly, the arc-mode discharge phenomenon will probably resume even more powerfully and we are likely to see a truly Great Comet over the coming weeks. But NOT for the “reasons” put forward by mainstream astronomy….
The observational evidence being provided by Ison (along with other comets) is to mainstream astronomy what the 17 year-long Pause is to mainstream CAGW. It’s called falsifying a theory.

Ulrich Elkmann
November 29, 2013 3:38 am

ISON, ISOFF, ISONAGAIN…
Schrödinger’s Comet.
But no comet Icarus. It should be Ideadalus. Btw, “Icarus” has already been pinned on asteroid 1566.

Ulrich Elkmann
November 29, 2013 3:39 am

Oops. “Idaedalusson”, of course.

French_Atkins
November 29, 2013 3:45 am

Sorry, not “arc-mode discharge phenomenon” but “GLOW-mode discharge phenomenon” (otherwise Ison would disintegrate for sure, as it may still do if the electric stress created by excess voltage difference becomes too great…).

November 29, 2013 3:54 am

Perhaps if all our predictions end up being wrong, we should examine our theory and assumptions?
I’m always tickled by the quotes from people describing the formation of comets from slow ice and dust accretion. It’s not that it is inherently implausible, it’s just that speculation is not fact just because some guy believes it. The one strong data point we have (Deep Impact / Comet Tempel 1) indicates that comets have a lot more cohesion than previously thought.
For a skeptical site – and one I greatly appreciate – I am always dismayed at the degree of dogmatic assertion accompanied by unexamined assumptions that one reads in comments here, and from some of the smartest and most insightful commenters in other respects.

November 29, 2013 4:11 am

>UPDATE3: Now it seems back again…
While you’re in an updating mode, you need to go back an update your initial scoop on Ison:
“Spectacular video: Comet ISON imaged from a Langrange [sic] point in space”
http://wattsupwiththat.com/2013/11/26/spectacular-video-comet-ison-imaged-from-a-langrange-point-in-space/
The referenced satellite imagers, STEREO A and B, are _not_ parked at the Lagrangian points L4 and L5, as reported.

See - owe to Rich
November 29, 2013 4:16 am

Dang it, I’ve been over on the previous thread http://wattsupwiththat.com/2013/11/27/watch-live-updates-on-comet-ison/#comment-1487038 talking to myself not realizing there was this thread! Over there you’ll see comments wherein I claimed ISON wasn’t dead at November 28 2151UT. And that it is continuing to brighten again.
Rich.

meemoe_uk
November 29, 2013 5:01 am

I looked at you posts owe to Rich.
1minute b4 you posted
” but from my view of LASCO C2 20:36UT (74 minutes ago) a small remnant has survived.”
I posted…
“It’s now looks like ISON survived the arc discharge without serious damage.”
So i beat ya
:p

See - owe to Rich
November 29, 2013 5:02 am

meemoe_uk said:

I’ll accept my noble prize on 3pm on Friday after I’ve collected my dole check. Just beaten the all the world’s professional astronomers to the correct conclusion on the non-fragmentation of Ison in its solar encounter.

I believe that Nobel/noble prizes can be shared by a small group, so in light of my earlier comments on the other thread I offer myself up as a co-conspirator! /sarc
It looks as if the coma of ISON was completely blown away leaving only the nucleus which was too small to be seen, hence the reports of “demise”. Probably many comets have done this in the past but it is only now that we have the technology to even try and see what is going on – and then failed effectively! In the old days people saw a comet approach the Sun, lost sight of it, and saw it come back out again; they didn’t know what happened to it at perihelion.
Regarding the tidal phenomenon, one can think of it as the near side of the comet is trying to follow a slightly different orbit from the far side (going to ignore rotation here), so it does require some cohesive force to hold it together. I don’t know why no-one has done the maths to work out whether a 2km body’s own gravity is enough to counter the tidal force at ISON’s perihelion position. Leif?
A further question would be whether, if part of it was pulled slightly apart, as it moves further away from the Sun and the inverse cube effect decreases more rapidly than its own internal inverse square effect, could it come back together again? Someone, somewhere, may already have calculated this sort of thing.
And then there are the variable internal structural forces to consider, if as people say it is more rock than ice.
Anyway, it’s a privilege to be witnessing this,
Rich.

See - owe to Rich
November 29, 2013 5:10 am

meemoe_uk (“So i beat ya”) – we just cross-posted. I might just give you the biscuit. It’s true that when I said “small remnant” I did think that the nucleus might have been seriously reduced in size. I don’t think we’ll ever really know, because even now good estimates of nucleus size seem difficult because they are so small compared to the obscuring coma.
Anyway, well done mate! (I may withdraw that if I can’t see it even with binoculars.)
Rich.

November 29, 2013 5:21 am

@Scuzza Man

For a skeptical site – and one I greatly appreciate – I am always dismayed at the degree of dogmatic assertion accompanied by unexamined assumptions that one reads in comments here, and from some of the smartest and most insightful commenters in other respects.

Great comment, I totally agree. The MSM is dominated by empty-headed “drive-by” journalism and sensationalism. We don’t want that to happen here on this blog, which should always strive to be scientifically accurate and unbiased.
😐

Bruce Cobb
November 29, 2013 5:28 am

Well then, I guess if ISON could speak, it would say “the report of my death was an exaggeration”.

French_Atkins
November 29, 2013 5:32 am

As of 14.24 French time, NASA is still claiming “Comet ISON Fizzles as it Rounds the Sun”:
http://www.nasa.gov/content/goddard/comet-ison-fizzles-as-it-rounds-the-sun/#.UpiRr9JDu1g
Presumably, they’re still looking for the right words to cope with the incomprehensible (because uncomprehended) update.

TomR,Worc,MA,USA
November 29, 2013 5:42 am

When is going to be the best view we will get from earth of ISON, or is it too late?

Jerker Andersson
November 29, 2013 5:48 am

Ison 1 – Sun 0
Ison is brightening fast as it leaves the suns corona, similar to other sun grazers that loose their tail and surrounding gas cloud as they get too close to the sun.
http://soho.esac.esa.int/data/realtime/c3/512/

Matt Schilling
November 29, 2013 5:51 am

This seems like a good time and thread to mention the late, great astronomer Dr. Thomas C. Van Flandern’s web site http://www.metaresearch.org. He asserted comets and asteroids were essentially the same thing – the remnants of one or more exploded planets. (It seems Mars was the moon of one of these doomed giant planets.) I don’t recall ever seeing metaresearch.org mentioned on this site. I love it for his well thought out, out of the mainstream thinking.

November 29, 2013 6:20 am

Bill Jamison says November 28, 2013 at 11:41 pm
Comet ISON will forever be known as the zombie comet.

A better fit, perhaps the Lazarus-comet? (looks to predate the term ‘zombie’ by centuries; Zombiw was first used, it appears, by Canadian anthropologist and ethnobotanist Wade Davis in Haiti in 1982 or so to describe a particular human ‘state’ he had observed)
.

martin m
November 29, 2013 6:32 am

If only were IPCC…

See - owe to Rich
November 29, 2013 6:33 am

It seems unlikely that “zombie” was first used in 1982 given that there was a pop band called “The Zombies” in the mid-sixties. I remember the classic song “She’s Not There”.
Perhaps ISON should be called the just-like-climate-change-it’s-totally-normal comet 🙂 That’s another one for #ClimateThanks !
Richard.

Editor
November 29, 2013 6:33 am

meemoe_uk says:
November 29, 2013 at 2:04 am

What’s with the ‘its a snowball’ myth?
http://en.wikipedia.org/wiki/File:Tempel_Impactor_150Km.jpg
NASA went to all that effort to photograph a comet up close in 2005 and got hard evidence that they are rocks, not ice.

“Rocks”? “They”? What broke up SL-9 near Jupiter? Not much solar heating there, you can do the math, ISON got to some 0.013 AU of the Sun before breaking up.
From http://en.wikipedia.org/wiki/Deep_Impact_%28spacecraft%29 :

Initial results were surprising as the material excavated by the impact contained more dust and less ice than had been expected. The only models of cometary structure astronomers could positively rule out were the very porous models which had comets as loose aggregates of material. In addition, the material was finer than expected; scientists compared it to talcum powder rather than sand.[37] Other materials found while studying the impact included clays, carbonates, sodium, and crystalline silicates which were found by studying the spectroscopy of the impact.[12] Clays and carbonates usually require liquid water to form and sodium is rare in space.[38] Observations also revealed that the comet was about 75% empty space, and one astronomer compared the outer layers of the comet to the same makeup of a snow bank.

November 29, 2013 6:52 am

See – owe to Rich says:
November 29, 2013 at 5:02 am
I don’t know why no-one has done the maths to work out whether a 2km body’s own gravity is enough to counter the tidal force at ISON’s perihelion position. Leif?
One way of getting a feel for this is to calculate the gravitational accelerations. For the Sun at ISON’s closest approach gSun = 33.4 m/s/s i.e. only about three times that we enjoy on the surface of the Earth. The difference in gSun that the 2 km diameter of ISON makes is 0.00007 m/s/s. ISON’s own g force is [based on a mass of 3E12 kg] is 0.00020 m/s/s or three times larger than the tidal force. If ISON has ANY cohesion at all [like rock or even a snowball] that just adds to the difficulty of tidal breakup.

November 29, 2013 7:10 am

See – owe to Rich says:
November 29, 2013 at 5:02 am
I don’t know why no-one has done the maths to work out whether a 2km body’s own gravity is enough to counter the tidal force at ISON’s perihelion position. Leif?
The distance within which tidal breakup occurs is called the Roche-limit. Wikipedia has a good article on that http://en.wikipedia.org/wiki/Roche_limit but the table for selected examples is wrong [the unit should be km not meter]. Anyway, you can see that ISON is outside the Roche limit.

November 29, 2013 7:15 am

See – owe to Rich says November 29, 2013 at 6:33 am
It seems unlikely that “zombie” was first used in 1982 …

pop-culture references or first use by a ‘scientist’?
‘Zombie-ism’, per se, has been known as part of voodoo (more correctly: Vodou).
Haitian Creole: zonbi – http://en.wikipedia.org/wiki/Zombie
“Zombi” is also another name of the Vodou snake lwa Damballah Wedo, of Niger–Congo origin; it is akin to the Kikongo word nzambi, which means “god”. There also exists within the West African Vodun tradition the zombi astral, which is a part of the human soul that is captured by a bokor and used to enhance the bokor’s power.
.

November 29, 2013 7:20 am

Could add: “The most well-known researcher to explore the Haitian zonbi is Wade Davis, an ethnobotanist:” per http://www.umich.edu/~uncanny/zombies.html

November 29, 2013 7:23 am

French_Atkins says:
November 29, 2013 at 3:29 am
As a fellow “astronomo-sceptic”, I totally agree with what meemoe_uk has been saying about an electric interpretation of what is unfolding before us.
Man, your ignorance runs deep.

November 29, 2013 7:24 am

@_Jim
> Zombiw was first used, it appears, by Canadian anthropologist
> and ethnobotanist Wade Davis in Haiti in 1982
The Wikipedia article you are quoting doesn’t say that Davis was the first to use the word. Need to consult an etymology dictionary, which shows word origins:
http://www.etymonline.com/index.php?allowed_in_frame=0&search=zombie
zombie (n.)
1871, of West African origin (cf. Kikongo zumbi “fetish;” Kimbundu nzambi “god”), originally the name of a snake god, later with meaning “reanimated corpse” in voodoo cult. But perhaps also from Louisiana creole word meaning “phantom, ghost,” from Spanish sombra “shade, ghost.” Sense “slow-witted person” is recorded from 1936.

meemoe_uk
November 29, 2013 7:30 am

What broke up SL-9 near Jupiter?
It got zapped electrically. Same way all comets go.
ISON got to some 0.013 AU of the Sun before breaking up
Ison didn’t break up
New news :
Ok everyone, it’s now past 50% odds that Ison’s old trailing tail is going to fade away to obscurity, while the secondary angled at 90deg to its old tail is turning into its main tail.
What u think to that Leif?

November 29, 2013 7:32 am

French_Atkins says November 29, 2013 at 3:45 am
Sorry, not “arc-mode discharge phenomenon” but “GLOW-mode discharge phenomenon” (otherwise Ison would disintegrate for sure, as it may still do if the electric stress created by excess voltage difference becomes too great…).

As ‘glow’ generally involves ‘plasma’ processes (excited gases) and therefore requires gases at a certain pressure (probably non-existent in the vicinity of the comet) between which electrons travel, how would this modify the “GLOW-mode” discharge process (is this a discharge as in a Neon or Argon lamp)? A further question, what is the method of continuing ‘charge separation’ (or charge accumulation) such that the glow or discharge process may be continued (made continuous, to support continued or continuous glow, etc) by the comet-mass in order to achieve these phenoms?
.

Ulrich Elkmann
November 29, 2013 7:32 am

Some people’s pop cultural coolness needs to be improved. “Zombie” is definitely older than 1982. The modern shambling version goes/shambles back to “Night of the Living Dead” (1968); the classic Hollywood variety to Jacques Tourneur’s “I Walked with a Zombie” (1943).The Hollywood ur-example being “White Zombie” (1932; eminently shuddersome, but not for the Un-Grateful Dead). The concept was popularized by William Seabrook in “The Magic Island” (1929), which defined all the trashy voodoo/hoodoo concepts about Haiti while ignoring the sordid truth.

November 29, 2013 7:34 am

re: John Day says November 29, 2013 at 7:24 am
Already covered that aspect, but thanks anyway. (Day late and a dollar short.)

November 29, 2013 7:38 am

re: Ulrich Elkmann says November 29, 2013 at 7:32 am Some people’s pop cultural coolness needs to be improved. “Zombie” is definitely older than 1982.
See addenda above, and please, try to keep up …

November 29, 2013 7:42 am

meemoe_uk says:
November 29, 2013 at 7:30 am
while the secondary angled at 90deg to its old tail is turning into its main tail. What u think to that Leif?
A comet has three tails: an ion tail and two dust tails. The latter lie along the orbit and the former is directed away from the sun. So close to the sun there can be, and often is, a large angle between the two. This is quite normal and nothing special. http://en.wikipedia.org/wiki/Antitail

Fernando
November 29, 2013 7:42 am

?????…Any picture “optical” ???????

Jim G
November 29, 2013 7:54 am

lsvalgaard says:
“free fall” and reply.
Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force until one considers that it is moving in a straight line and space itself is curved causing the appearance of a hard turn. This is the deception of considering gravity as a force as opposed to a curvature of space/time. If a force were applied, as say a rocket engine, that would be a different story.

See - owe to Rich
November 29, 2013 8:01 am

Leif said: “The difference in gSun that the 2 km diameter of ISON makes is 0.00007 m/s/s. ISON’s own g force is [based on a mass of 3E12 kg] is 0.00020 m/s/s or three times larger than the tidal force.”
Thanks for coming up trumps Leif.
Rich.

See - owe to Rich
November 29, 2013 8:13 am

Jim G says: “This is the deception of considering gravity as a force as opposed to a curvature of space/time. If a force were applied, as say a rocket engine, that would be a different story.”
Jim, I’m sorry but I have to disagree; we don’t need Einsteinian mechanics for this, as Newtonian will do. The point about free fall is that, ignoring the tidal effect, every particle of the nucleus experiences the same force so they all accelerate equally and feel no internal stress. When we do take the tidal effect into account, so the near side is pulled a little harder than the far side, there is some measurable internal stress. Leif has kindly calculated it, and even if the nucleus consisted solely of tennis balls lightly glued together it would not come apart. (There would just be a nasty rubbery smell as they burnt off from the outside.)
Rich.

Jim G
November 29, 2013 8:15 am

More likely than whatever “forces” were in action, simply the heat and any CME particles or other paticulate matter acted like a shotgun on a clay pigeon.

Jim G
November 29, 2013 8:24 am

See – owe to Rich says:
My point is that when we think of gravity as a “force” we think wrong. When we think of it as a curvature of space there are no g-forces in the turn. The tidal “forces” are merely differences in that curvature and can, indeed, have effects. How we think of the situation keeps us from making wrong interpretations. I was not arguing with Leif. Such has little effect upon him in any event. No offense intended to him or you.

November 29, 2013 8:30 am

Jim G says:
November 29, 2013 at 8:24 am
I was not arguing with Leif. Such has little effect upon him in any event.
If your argument has merit it would have effect…

November 29, 2013 8:41 am

@_Jim
>Already covered that aspect, but thanks anyway. (Day late and a dollar short.)
Again you try to push the blame on others for your faulty replies.
You did not cover the chronology of this word usage with respect to the use of the word ‘zombie’ in popular American English culture. Instead you just dwellt on the social/anthropological signficance with respect to African and Haitian culture (“voudou” etc).
You failed to correct your claim of “1982” as the first usage of the word ‘zombie’ in American culture, even after it was pointed out by See-owe-2-Rich that 1982 could not be the earliest citation of that word.
I provided an English word origin date of 1871, citing a credible authority in word etymology.
So I it looks like you came up short, not me.
😐

Jim G
November 29, 2013 8:46 am

lsvalgaard says:
November 29, 2013 at 8:30 am
Jim G says:
November 29, 2013 at 8:24 am
“I was not arguing with Leif. Such has little effect upon him in any event.
If your argument has merit it would have effect…”
Doubtful, as you seem to most often consider yourself the final arbitor od “merit”. But Happy belated Thanksgiving in any event.

See - owe to Rich
November 29, 2013 8:49 am

Jim G, the problem with thinking of curved space(-time) is that it is only light that follows the curved space. So I think that the concept of force is more meaningful to most people. Only think Einsteinian physics when the velocity gets to be much more than 0.001c!
The more interesting question which I should like to see debated is: What Caused The Sudden Dissipation Of ISON’s Coma Just Before Perihelion?
Was it electrical? How could anything mechanical or thermodynamic explain the extreme rapidity?
Rich.

Gary Pearse
November 29, 2013 8:53 am

Jim G says:
November 29, 2013 at 8:24 am
“See – owe to Rich says:
My point is that when we think of gravity as a “force” we think wrong. When we think of it as a curvature of space there are no g-forces in the turn.”
So Jim G, if a star’s light were to near-graze the sun (Eddington’s famous photograph), it would be captured by the “groove” caused by the sun’s gravity and would forever circle the sun. Indeed, in your view of the phenomenon, the “groove” should capture all the comets that ever were and they should be in a merry-go-round forever. If there are no forces, how do nearly all comets pull themselves away from the sun once they have a close approach?

meemoe_uk
November 29, 2013 8:55 am

As ‘glow’ generally involves ‘plasma’ processes (excited gases) and therefore requires gases at a certain pressure (probably non-existent in the vicinity of the comet) between which electrons travel, how would this modify the “GLOW-mode” discharge process
If there was no plasma then the comet’s rocky surface would glow.
> (is this a discharge as in a Neon or Argon lamp)?
Yes , same thing.
A further question, what is the method of continuing ‘charge separation’ (or charge accumulation) such that the glow or discharge process may be continued (made continuous, to support continued or continuous glow, etc) by the comet-mass in order to achieve these phenoms?
As Leif insisted in prior exchanges with me, simple, common interaction between otherwise neutral molecules repeated en-mass can accumulate huge charge separation. Megavolt lightning storms on Earth accumulate by super cooled water colliding with ice in the clouds and striping charge. Rub 2 dry materials together, one will strip electrons from the other. It’s how a van-de-graf works, rubber on nylon or silk. On a hot dry day, driving in your car will build up charge of thousands of volts by friction with the air.
This common charge separation phenomena seen on Earth is even more present in space.
In space, the duration of charge build up is measured in years or decades or longer instead of seconds to hours and the surfaces being rubbed are orders of magnitude greater.
Comets experience the solar wind. The solar wind strips charge ( I don’t know which sign ) off the comet, like air striping charge of a moving car on a hot dry day. This goes on for years.
This way comets can spontaneously explode due to too much charge out in space. Also they are prone to discharge when they come close to another body. There is denser plasma near other bodies. Plasma that is denser is highly conductive.
props to Leif for helping me understand how massive charge separation in space occurs. It works for all bodies in space, not just comets.

Jim G
November 29, 2013 8:57 am

See – owe to Rich says:
November 29, 2013 at 8:49 am
“Jim G, the problem with thinking of curved space(-time) is that it is only light that follows the curved space.”
Anything traveling through space travels in a straight line unless acted upon by a force. If space is curved by mass in the vacinity then everything travels in a straight line through that curved space, not just light. The planet Mercury’s orbit was corrected from the Newtonian concept, which was wrong, by using relativity and the concept of curved space/time as a correction.

French_Atkins
November 29, 2013 9:01 am

lsvalgaard says:
November 29, 2013 at 7:23 am
French_Atkins says:
November 29, 2013 at 3:29 am
As a fellow “astronomo-sceptic”, I totally agree with what meemoe_uk has been saying about an electric interpretation of what is unfolding before us.
Man, your ignorance runs deep.
Many thanks for the compliment…
My understanding, after a couple of years of DAILY visits to WUWT, was that this site, unlike many others, is above this kind of gratuitous personal attack, which is based on neither observational evidence nor on straightforward logic. But perhaps I’ve been missing something…
In addition, you know absolutely nothing about me (the post you quote from was my first on WUWT). So what allows you to throw around this sort of ill-informed insult? Must I assume you’re part of the astronomy Establishment which is so consistently at an utter loss to explain the actual observations of comets (images of rocky, often blackened nuclei displaying cliffs,” impact craters” and clear electrical discharge features, “unbelievable” samples of minerals brought back from Comet Wild 2 by the Stardust Mission, that sort of thing) and still clings to the gaslight-era mantra of Fred Whipple’s “dirty snowball” model so as to try to still preserve the tattered patchwork of the BB theory?
Your failure to address the actual SUBSTANCE of my post, explaining WHY I “totally agree with what meemoe_uk” seems to me to say it all….
I repeat that “The observational evidence being provided by ISON (along with other comets) is to mainstream astronomy what the 17 year-long Pause is to mainstream CAGW. It’s called falsifying a theory.”

Jim G
November 29, 2013 9:04 am

Gary Pearse says:
November 29, 2013 at 8:53 am
Jim G says:
November 29, 2013 at 8:24 am
“See – owe to Rich says:
My point is that when we think of gravity as a “force” we think wrong. When we think of it as a curvature of space there are no g-forces in the turn.”
“So Jim G, if a star’s light were to near-graze the sun (Eddington’s famous photograph), it would be captured by the “groove” caused by the sun’s gravity and would forever circle the sun. Indeed, in your view of the phenomenon, the “groove” should capture all the comets that ever were and they should be in a merry-go-round forever. If there are no forces, how do nearly all comets pull themselves away from the sun once they have a close approach?”
Don’t catch your logic. There is no “groove”. It is not closed space, just curved, and if the comet approached at the correct angle and distance it could be captured of crash into the sun.

Jim G
November 29, 2013 9:08 am

Corrections to poor typing: “of merit” “or crash” in previous posts of mine.

November 29, 2013 9:11 am

Jim G says:
November 29, 2013 at 8:46 am
Doubtful, as you seem to most often consider yourself the final arbitor of “merit”.
An argument falls on its own demerit.
meemoe_uk says:
November 29, 2013 at 8:55 am
This common charge separation phenomena seen on Earth is even more present in space
The difference between the Earth and Space is that the air is not a conductor, but a space plasma is. In a plasma the conductivity is so high that any charge imbalance immediately shorts out, so there are no separated charges in Space.
French_Atkins says:
November 29, 2013 at 9:01 am
In addition, you know absolutely nothing about me
Your comment said all there is to say. There is nothing wrong with ignorance [I am ignorant of many things]. Willful ignorance, on the other hand, is an abomination.

Budahmon
November 29, 2013 9:16 am

Hollywood referenced Zombies as early as 1940 in “Ghost Breakers” with Bob Hope:

November 29, 2013 9:22 am

re: John Day says November 29, 2013 at 8:41 am
The facts are before us; if you insist on disputing them further I suggest given your previously cited ‘acumen, command of the facts and authority’ address/direct your complaints to their original sources (i.e. writers, authors and researchers at their various uni’s or websites.)
Good day. (I mean that as a departing salutation.)
.

November 29, 2013 9:25 am

re: meemoe_uk says November 29, 2013 at 8:55 am
Hand-waving and filibustering; you have made not any technical points that will withstand serious cross examination.
.

November 29, 2013 9:27 am

re: Budahmon says November 29, 2013 at 9:16 am
Someone else ‘behind the curve’. (Ppl, you have to keep up to be taken seriously on a rebuttal)
IOW, your ‘cite’ is a non-accredited pop-culture work.
.

French_Atkins
November 29, 2013 9:33 am

lsvalgaard says:
November 29, 2013 at 9:11 am
“ French_Atkins says:
November 29, 2013 at 9:01 am
In addition, you know absolutely nothing about me
Your comment said all there is to say. There is nothing wrong with ignorance [I am ignorant of many things]. Willful ignorance, on the other hand, is an abomination.”
OK Mister Isvalgaard. Game over. I didn’t understand where you were coming from straight away. I’ve got better things to do than to be drawn into swapping proverbs….
Glad anyway that you have nothing to say about the substance of my posts.

November 29, 2013 9:35 am

@Jim G
>Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force …
You seem to be thinking of the forces you would feel in roller coaster ride: every turn, sharp or not, is sensible to the occupants of the trolley.
But a roller-coaster trolley is not in free fall. It’s constrained by the rails to go in directions it would not naturally go (if not constrained). That what causes the forces you feel.
Thought experiment: imagine you’re in a roller coaster, where the trolley breaks free from the rails. _Now_ you’re in “free fall”. For the duration of the ride you will feel no forces.
Assume the roller coaster was on top of Comet Ison, when it breaks free. Now you’re still “falling”, being pulled towards the Sun by its gravity.But your velocity (and the comet) has a large horizontal component, such that your motion vector points away from the Sun, towards Earth. So you (and the comet) are still technically falling, feeling no forces, even though you’re in an elliptical orbit which will eventually carry you to the outer limits of the solar system.
The only forces you might feel are braking forces caused by “atmospheric drag” or if you’re ‘struck’ by plasma filaments shooting out from the photosphere. But the corona “atmosphere” is too thin for you to feel any braking forces. And the filaments also are very thin, but could exert a force on you. But these forces are evidently very small because the imagery seems to show Zombie-Ison moving in what looks like a ‘free-falling’ orbit, i.e. not being pushed laterally into multiple paths. It’s pretty much like a vacuum up there. The _total_ mass of the corona is about 1% the mass of the entire Martian atmosphere, which is already pretty thin. Imagine Mars’ atmosphere expanded to solar proporitions.
😐

November 29, 2013 9:36 am

French_Atkins says:
November 29, 2013 at 9:33 am
Glad anyway that you have nothing to say about the substance of my posts.
There is nothing to say because there is no substance.
If you need a general refutation of EU, this link is a good place to start: http://dealingwithcreationisminastronomy.blogspot.com/p/challenges-for-electric-universe.html

Jim G
November 29, 2013 9:40 am

lsvalgaard says:
November 29, 2013 at 9:11 am
Jim G says:
November 29, 2013 at 8:46 am
“Doubtful, as you seem to most often consider yourself the final arbitor of “merit”.
An argument falls on its own demerit.”
AH, but even observational data is subject to good or poor, sampling, gathering, ad hoc changes, statistical analysis and that nasty old “interpretation” and the political correctness lemming instinct. For example, consider the models proclaiming CO2 to be the main causal factor in global warming, or er climate change or whatever they now call it. So, who determines the merit?

Jim G
November 29, 2013 9:43 am

John Day says:
November 29, 2013 at 9:35 am
@Jim G
>Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force …
That is why I said to think of it as curved space, NOT a force! Read what I said.

November 29, 2013 9:43 am

Jim G says:
November 29, 2013 at 9:40 am
So, who determines the merit?
Everybody must determine the merit for himself, based on experience, belief, agenda, etc.

u.k.(us)
November 29, 2013 9:48 am

lsvalgaard says:
November 29, 2013 at 9:11 am
“Willful ignorance, on the other hand, is an abomination.”
=============
What about feigning ignorance ?, in an attempt to pick a commenters mind ?
I read and try to grasp all your comments.
(that was a compliment).

November 29, 2013 9:50 am

@me
>Imagine Mars’ atmosphere expanded to solar proporitions.
… and then divide that density by 100. That’s the density of the corona (probaby would be called a ‘good vacuum’ on Earth)

November 29, 2013 9:51 am

u.k.(us) says:
November 29, 2013 at 9:48 am
What about feigning ignorance ?, in an attempt to pick a commenters mind ?
would be OK in my book. To a point, though. The attempt has to be sincere.

Jim G
November 29, 2013 9:51 am

lsvalgaard says:
November 29, 2013 at 9:43 am
Jim G says:
November 29, 2013 at 9:40 am
So, who determines the merit?
“Everybody must determine the merit for himself, based on experience, belief, agenda, etc.”
This scares me, but you have my agreement.

meemoe_uk
November 29, 2013 10:03 am

How are you getting on with the idea of a electric double layers in space plasma Leif?
Hannes Alfvén pointed out that: “In a low density plasma, localized space charge regions may build up large potential drops over distances of the order of some tens of the Debye lengths. Such regions have been called electric double layers.
In other words, what with all the different densities, temperatures, motion, ionizations and currents of plasma in different regions of space, debye shields are everywhere in space, shielding off many charge imbalances that would otherwise short out.
It’s the case with comets for sure dude, and everything else.
>Hand-waving and filibustering; you have made not any technical points that will withstand serious cross examination.
All I’m reading is you aren’t knowledgeable enough to debate me. Don’t worry Leif will carry the conventional side of the debate now.

November 29, 2013 10:15 am

@Jim G
>That is why I said to think of it as curved space, NOT a force! Read what I said.
I did.
Somehow you think the notion of ‘curved space’ is necessary to understand gravitional mechanics. It’s not. Newton conceived all of this (including orbiting satellites in free fall) without having any idea of space-time curvature.
Your problem may be that you think of a force as a ‘sensation’. In physics, it’s not. A force is simply defined as a ‘change in motion’. The Latin word for ‘motion’ is ‘momentum’, which Newton defined as mass times velocity (mv). His briliant contribution to science was the realization that changes in motion (i.e. mv) are the causes of forces. In fact, he discovered that the rate of change of motion _is_ the force:
F = d(mv)/dt = ma (for constant mass m)
http://en.wikipedia.org/wiki/Force
But you will protest “The path of your so-called ‘falling comet’ is _curved_. That’s a change in motion, so there must be a force. Ha!”
But the force needed to bend the path is orthogonal to the path vector and exactly equal to the gravitional force, so the net force is zero. So objects in such ‘free fall’ behave as if they’re weightless, which means they will not be able to feel the force causing the curved path.

Mac the Knife
November 29, 2013 10:15 am

Will spectrum data be available, summarizing elemental content of the ejecta from the ‘disintegration’ event at close approach? A 3-way comparison of before, during, and after close approach might be interesting!

See - owe to Rich
November 29, 2013 10:18 am

Unfortunately, having agreed so much with Leif so far on this thread, I’m going to have to raise an issue or three here.

1.

Jim G says:
November 29, 2013 at 8:46 am
Doubtful, as you seem to most often consider yourself the final arbitor of “merit”.
An argument falls on its own demerit.

But not everyone agrees on merit. That is why there exist things like “consensus” and “minority report”. Consensus isn’t always correct. But on a blog it is usual to try to persuade, and then a consensus comes along with you.
2.

meemoe_uk says:
November 29, 2013 at 8:55 am
This common charge separation phenomena seen on Earth is even more present in space
The difference between the Earth and Space is that the air is not a conductor, but a space plasma is. In a plasma the conductivity is so high that any charge imbalance immediately shorts out, so there are no separated charges in Space.

I don’t think I buy that all parts of space have high conductance with all other parts. But then, I probably am a bit ignorant on the subject of plasmas. But why can’t you have a plasma with one connected charge in one place, and another in another place, and then if they meet you get a big surge?
3.

French_Atkins says:
November 29, 2013 at 9:01 am
In addition, you know absolutely nothing about me
Your comment said all there is to say. There is nothing wrong with ignorance [I am ignorant of many things]. Willful ignorance, on the other hand, is an abomination.

Which is the greater abomination: willful ignorance or willful rudeness? Leif, please, things go a lot better here when we hear more details of your scientific knowledge and less of your bombast. From what I am reading there are still lots of surprising things about comets from which we might learn new theory. Or perhaps I mean new practice, as in unusual combinations of physical effects but still within the so-far known laws of physics.
Regards,
Rich.

November 29, 2013 10:20 am

meemoe_uk says:
November 29, 2013 at 10:03 am
Hannes Alfvén pointed out that: “In a low density plasma, localized space charge regions may build up large potential drops over distances of the order of some tens of the Debye lengths. Such regions have been called electric double layers.
You conveniently omitted the rest of his comment: “An electric double layer is the simplest space charge distribution that gives a potential drop in the layer and a vanishing electric field on each side of the layer. In the laboratory, double layers have been studied for half a century, but their importance in cosmic plasmas has not been generally recognized.”
And for good reason. The Debye length in the solar wind and interstellar space is very small, of the order of 10 meter. And you gloss over the “localized space charge regions”. This means that the must be a process that maintains the separation. Furthermore if there is a large potential drop, any charge would be propelled rapidly across the double layer shorting out the imbalance, unless the separation process continues. A space plasma is in general so thin that it is collision-less. Charge separation can happen if the plasma is moved across a magnetic field [as happens in the Earth’s magnetosphere] but since in a space plasma far from stationary magnetic fields [like the Earth’s] the magnetic field is frozen into the plasma [as Alfvén taught us] it does not move across any field and separation does not occur.
All I’m reading is you aren’t knowledgeable enough to debate me
The EU stuff is ‘not even wrong’ and cannot be meaningfully debated, only rejected.

November 29, 2013 10:33 am

See – owe to Rich says:
November 29, 2013 at 10:18 am
I don’t think I buy that all parts of space have high conductance with all other parts. But then, I probably am a bit ignorant on the subject of plasmas.
yes that is it.
But why can’t you have a plasma with one connected charge in one place, and another in another place, and then if they meet you get a big surge?
You can, and that is exactly the point. After the surge the charge imbalance is gone.
Which is the greater abomination: willful ignorance or willful rudeness?
I call it as I see it. ‘Rude’ or not. Misinformation must be combated, if it hurts the misinformer’s feelings.
From what I am reading there are still lots of surprising things about comets from which we might learn new theory. Or perhaps I mean new practice, as in unusual combinations of physical effects but still within the so-far known laws of physics.
There are indeed many things to learn and we learn all the time. The EU-cult generally ignores what is being learned, as the adherents already ‘know’ all what is going on. Such cult-following in antithetic to science.

French_Atkins
November 29, 2013 10:44 am

lsvalgaard says:
November 29, 2013 at 9:36 am
French_Atkins says:
November 29, 2013 at 9:33 am
Glad anyway that you have nothing to say about the substance of my posts.
“There is nothing to say because there is no substance.
If you need a general refutation of EU, this link is a good place to start:http://dealingwithcreationisminastronomy.blogspot.com/p/challenges-for-electric-universe.html
I have nothing against a site which, on the face of it, combats creationist ideas in astronomy, quite the contrary in fact: one of the reasons why I turned away some years ago from the Big Bang theory was precisely that it is the BB which enshrines the ULTIMATE creationist theory. EU theory, on the other hand has absolutely NOTHING to say about the nature or the time of the origin of the Universe. This is already a huge step forward in scientific thinking: I’m not saying I don’t believe in a possible Initial Creation, but simply that we can obviously know nothing about it, as Big Bangers claim we can.
Apart from that, I don’t need a refutation of EU, because it proceeds from correct scientific method in that it is evidence-based, in the same way that climate skepticism is evidence-based. I went down the same intellectual path in moving from Big Bang to EU theory as I did a year or so later in switching from the warmist camp to the climate-skeptic camp, once I had realized that the same forms of obfuscation were being practiced in both so-called “sciences”. Elegant maths and computer models can do nothing in the face of hard, irrefutable, observational evidence, whatever the field under study.

November 29, 2013 10:55 am

French_Atkins says:
November 29, 2013 at 10:44 am
the BB which enshrines the ULTIMATE creationist theory.
Indeed, we have learned a lot about when and how the universe was created 13.8 billions years ago.
EU theory, on the other hand has absolutely NOTHING to say about the nature or the time of the origin of the Universe.
And by asserting that you throw out the greatest story of all, based on precision observations. Don’t you see that by willfully wearing blinkers you are missing the glorious picture of where and when we came from that we have teased out of the wonderfully precise observations of the past ten years? I guess you do not. Correct me if I am wrong.
On a technical point: there was no plasma in the Universe starting about 380,000 after the BB and for the next several hundred millions years, at which time gravity had caused the first stars to form and by their UV radiation ionize the intergalactic medium. What does that fact do to EU theory?

November 29, 2013 11:08 am

So back to ISON, any predictions as to what will happen to it. Will not the stuff that melted refreeze and kind of all come back together again. The (ice and rocks) didn’t disappear and should still be loosely connected (as was stated with the tennis balls lightly glued together). Isn’t the material all there in some form?

Editor
November 29, 2013 11:10 am

Jim G says:
November 29, 2013 at 9:43 am
John Day says:
November 29, 2013 at 9:35 am
@Jim G
>Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force …
That is why I said to think of it as curved space, NOT a force! Read what I said.

Whoa, I tend to think of curved space as something more related to a racetrack or one of those gravity well demos at science museums. There the accelerating force come from the track and is propagated throughout the body that’s turning. In free fall all the atoms involved are being accelerated at (nearly) the same amount.
I have no trouble seeing high accelerations in freefall due to strong gravitational fields – heck, the acceleration of gravity at the ISS is still close to 10 m/s/s, the only reason the astronauts are weightless is because they’re accelerating at the same rate – free fall. (I think it was Douglas Adams who said the way to orbit a planet is to through yourself at the ground – and miss.)

Editor
November 29, 2013 11:17 am

J. Philip Peterson says:
November 29, 2013 at 11:08 am

So back to ISON, any predictions as to what will happen to it. Will not the stuff that melted refreeze and kind of all come back together again. The (ice and rocks) didn’t disappear and should still be loosely connected (as was stated with the tennis balls lightly glued together). Isn’t the material all there in some form?

Comets are notoriously unpredictable and this one seems much worse than most. I wouldn’t be surprised it it behaves perfectly predictably for the rest of its trip out.
The comet did shed a lot of material, the “poof” near perihelion was pretty clear. What’s left is somewhere between a small fragment and a lot. Lets give the poor thing a few days to get away from the extreme heating, solar wind, and all that. Then I think people will have a better chance to figure out what’s left and what’s in store.

u.k.(us)
November 29, 2013 11:21 am

OK, now that science has been “settled” above :)…..do we still have a comet or what ?

November 29, 2013 11:27 am

lsvalgaard @ November 29, 2013 at 9:36 am
Thanks for that link Professor Leif. I have been skirmishing with a friend who has fallen hook, line and sinker for the codswallop otherwise known as the EU hypothesis. My weapons bay is now fully loaded for a final, decisive battle.

Steve Oregon
November 29, 2013 11:27 am

Comets are like people.
Comets come, comets go.
As do opportunities for dispute and disparagement.
Some blow up, others diminish, some are resolved and a few are never ending.
Now what about the poor Cometeers? The comet residents? They must be having a tough go of it.
Let’s not pretend that we are certain there is no life form on the comet. There very well could be and in a form we cannot fathom.
I’ll bet we could even strike up a nasty argument over the intricacies of their existence and their impacts on the universe. After all they are wandering the solar system leaving behind a comet comtrail of unknown composition. Suppose this comet is distributing ions of horrific stuff discharged by the inhabitants like refuse disposal.
Should we not try and stop them?
I am deeply troubled by the possibilities.
Oh I’m sorry, just snip my idiocy.

French_Atkins
November 29, 2013 11:34 am

lsvalgaard says:
November 29, 2013 at 10:55 am
French_Atkins says:
“EU theory, on the other hand has absolutely NOTHING to say about the nature or the time of the origin of the Universe”.
And by asserting that you throw out the greatest story of all, based on precision observations. Don’t you see that by willfully wearing blinkers you are missing the glorious picture of where and when we came from that we have teased out of the wonderfully precise observations of the past ten years? I guess you do not. Correct me if I am wrong.
I don’t think I can “correct” you because I can’t be sure you’re “wrong” since you’re talking poetry and poetry doesn’t aim to address issues requiring the exchange of information….
“On a technical point: there was no plasma in the Universe starting about 380,000 after the BB and for the next several hundred millions years, at which time gravity had caused the first stars to form and by their UV radiation ionize the intergalactic medium. What does that fact do to EU theory?”
I think you’re missing the point… The sort of sterile circular logic you are using, where the only possible answers are necessarily dictated by the presuppositions contained in the question itself is strangely akin to that underlying the question “Have you stopped beating your wife?” (I don’t expect an answer, either).
Sorry if you still think that my “ignorance runs deep”…

November 29, 2013 11:36 am

French_Atkins says:
November 29, 2013 at 11:34 am
Sorry if you still think that my “ignorance runs deep”…
You just demonstrated more of it…

u.k.(us)
November 29, 2013 11:40 am

Steve Oregon says:
November 29, 2013 at 11:27 am
===============
Too late now, you said that out loud 🙂

See - owe to Rich
November 29, 2013 11:46 am

J. Philip Peterson.
Yes, back to ISON and what is going to happen to it? Also what happened to it when the coma got blown away near perihelion, as I asked before? Leif, I appreciate your comments in reply to me above, even if I don’t 100% agree, but now: what is your theory for what happened to that coma? Electrical or not electrical?
I’ll be back in 12 hours to check the answers…
Rich.

theButcher
November 29, 2013 11:46 am

From what angle are these shots taken from? From this perspective it appears the comet is quite large compared to the sun…

November 29, 2013 11:56 am

See – owe to Rich says:
November 29, 2013 at 11:46 am
what happened to that coma? Electrical or not electrical?
The coma is primarily water and some dust. The Water is destroyed by photodissociation: H2O + 2 photons (light) → 2 e- + 2 H+ + O. The protons and electrons are charged and can be picked up by the expanding corona and carried away. Also, simply light pressure plays a role in pushing the coma away. In addition, it is HOT so close to the Sun.

French_Atkins
November 29, 2013 12:06 pm

lsvalgaard says:
November 29, 2013 at 11:36 am
French_Atkins says:
November 29, 2013 at 11:34 am
Sorry if you still think that my “ignorance runs deep”…
You just demonstrated more of it…
GAME OVER

November 29, 2013 12:08 pm

French_Atkins says:
November 29, 2013 at 12:06 pm
GAME OVER
You throwing in the towel is accepted. Have a nice day.

November 29, 2013 12:09 pm

@_Jim
> The facts are before us; if you insist on disputing them further
What facts? I didn’t dispute your ‘1982’ claim. “CO2-Rich” did. And he was right.
All I did was to give you a more credible date: 1871. Are you disputing that?
Your snarky responses have brought on these retributions. Again you seem to blame others for things you failed to do. You really don’t see that do you?
😐

David L. Hagen
November 29, 2013 12:20 pm

In A Comparison Between Comets ISON and Lovejoy (2011) Roy Spencer posts the SOHO LASCO C3 vid with the comet ISON (or whats left) swinging out from the sun.

meemoe_uk
November 29, 2013 12:25 pm

You conveniently omitted..
Yes, but for clarity, not obfuscation. I’m not going to quote a whole paper for 1 sentence.
Your reply strikes me I’m correct with my debye shielding is a crucial point that makes EU theory plausible. You seem to be trying confound me with irrelevant detail and flawed logic.
I’ll dissect everything you wrote…
The Debye length in the solar wind and interstellar space is very small, of the order of 10 meter.
No problem for the EU case. electrodynamics and plasma are extremely scalable. Microscopic and even some nanoscopic plasma structures are mimicked by macro and cosmological structures. There’s no reason the functionality of the shield will be impaired at this scale.
And you gloss over the “localized space charge regions”.
What specifics do think need unglossing?
This means that the must be a process that maintains the separation.( of a double layer )
Yup. Tis the case with most if not all double layers. I know cos the EU guys said so. still no prob so far.
Furthermore…
? You haven’t pointed out any flaw so far so this adverb is inappropriate.
if there is a large potential drop, any charge would be propelled rapidly across the double layer shorting out the imbalance, unless the separation process continues.
( For strong double layers which your argument seems to suit more… )
…No, not just any charge. It would need have unusually high KE to overcome the potential barrier. But this does happen, indeed its how the potential builds up in the 1st place.
The potential barriers are ( counter intuitively if you’ve only studied electrostatics ) in the direction such that charge separation is maintained, not shorted.
And indeed, since plasma double layers are mostly, if not always, only a feature of dynamics, then the causal process is assumed to always continue. If it stops then electro-static forces become dominant and all connected charge separation is shorted out.
So far, still nothing to discredit debye shields in space.
Charge separation can happen if the plasma is moved across a magnetic field
Yup, electromagnetic induction.
It can also happen if 2 different materials are in dynamic contact, such as rubbing or particle collision.
Still everything ok with debye shields in space.
but since in a space plasma far from stationary magnetic fields [like the Earth’s] the magnetic field is frozen into the plasma [as Alfvén taught us] it does not move across any field and separation does not occur.
Ah, the magic wand of ‘frozen magnetic fields’ .
a.) You use it to say magnetic induction via Earth’s field fails to maintain a debye shield. Well guess what? My material contact rational for charge separation doesn’t require use of magnetic induction, so your argument has no bearing on mine.
b.) Alfven didn’t like his frozen magnetic field concept, he later described it as “pseudopedagogical”. And he didn’t accept the ideas that arise from strict adherence to frozen mag fields, such as magnetic reconnection. Which all electrical engineers agree is tripe. Only astronomers with there black holes, dark matter and zoo of exotic never detected particles and fields can accept such fiction.
c.) the magnetic field of Earth disagrees with you. There are charge separated regions in Earth’s magnetosphere.
So, even Leif, the Arch enemy of the EU, has nothing to discredit debye shields all over the cosmos. And you didn’t stress alfven’s last sentence in that quote, for bad reason it seems.
In the laboratory, double layers have been studied for half a century, but their importance in cosmic plasmas has not been generally recognized.”
The great man was right. Now the EU community recognizes there importance.

French_Atkins
November 29, 2013 12:33 pm

lsvalgaard says:
November 29, 2013 at 12:08 pm
French_Atkins says:
November 29, 2013 at 12:06 pm
GAME OVER
You throwing in the towel is accepted. Have a nice day.
Thanks, you too. And whatever you do, please don’t stop throwing out your proverbs, poetry, pleonasms and platitudes. It makes a nice change from serious science.

November 29, 2013 12:51 pm

meemoe_uk says November 29, 2013 at 10:03 am

All I’m reading is you aren’t knowledgeable enough to debate me. Don’t worry Leif will carry the conventional side of the debate now.

Hand-wavers simply wave their hands more (until flight is achieved as they leave the surface of the planet); how productive is that in a debate (literally: time and time again simple, yet incorrect assertions are made seirally … is this meant to ‘wear down’ the opposition, like CAGW accolades appear to do to skeptics)?
Even the ‘elementary physics’ they (wand wavers) cite they do not understand let alone know how it ‘works’. The beginnings of a proper education can be had though, at no cost to me (as contrasted with the case where I were to be involved in so-called on-line ‘debate’) by surveying the MIT physics courses available 24/7 on-line. http://ocw.mit.edu/courses/physics/
Maybe minds are ‘polluted’ with the this ‘Electric Universe’ stuff; perhaps an intervention is required? See: Electric Universe: Making Electric Fields
I excerpt, for education purposes only, the following:

Because it is difficult to form electric fields over large scales for long durations in nature! In nature, we largely encounter matter in the neutral state. There, the strongest and longest lasting electric fields exist at atomic scales, between atomic nuclei and their bound electrons.
Our experience with electric fields on everyday scales requires the input of energy from some other source.
Want an electrostatic field? Apply some rubbing energy between dissimilar fabrics (Wikipedia: Triboelectric effect). You must apply energy to separate the charges. Where does that energy come from? How long does the electric field last before it returns to an electrically neutral state? Not very long!
Lightning? You need moving gases containing dust and precipitation to slowly build up an electric field that can sustain a discharge. The energy to do this ultimately comes from the motions of gas and dust [involving ice particles, seems to the the thinking today] ultimately driven by heating and other forces. Again, the energy to separate the charges comes from other sources. Again, the discharge moves the system to a more electrically neutral configuration, very fast.
Even the plasmas in space must be at high temperatures to maintain ionization by collisions or other processes, or they must have sufficiently low density that the ions and electrons do not quickly collisionally recombine to neutral atoms. Let the plasma cool too much and you’ll soon be back to neutral atoms. Even then, you only get electric fields of a transient nature.
Electric fields are most easily created by charge separation (the other mechanism, by Maxwell’s equations, is induction, but EU supporters deny many of those processes which mainstream astrophysics has identified in the space environment).
Charge separation takes energy. EU wants to take electric fields as a given …

u.k.(us)
November 29, 2013 12:53 pm

French_Atkins says:
November 29, 2013 at 12:33 pm
lsvalgaard says:
November 29, 2013 at 12:08 pm
French_Atkins says:
November 29, 2013 at 12:06 pm
GAME OVER
You throwing in the towel is accepted. Have a nice day.
Thanks, you too. And whatever you do, please don’t stop throwing out your proverbs, poetry, pleonasms and platitudes. It makes a nice change from serious science.
++++++++++++++++
And just where do you think this comment might take you ?, back into the realm of science ?,you didn’t present any.
You had your dictionary opened to the “p” section, by the looks of your comment ?

November 29, 2013 12:56 pm

meemoe_uk says:
November 29, 2013 at 12:25 pm
The great man was right. Now the EU community recognizes there importance.
Real science has moved on and it seems that the EU is stuck. Nothing you have said makes any sense, but this is nothing new.
French_Atkins says:
November 29, 2013 at 12:33 pm
And whatever you do, please don’t stop throwing out your proverbs, poetry, pleonasms and platitudes.
You earn them.

November 29, 2013 1:00 pm

ISON ISOFF ISON again!
This looks like a comet to me,
http://sohowww.nascom.nasa.gov/data/realtime/c3/512/
It appears Comet ISON has survived after all.

November 29, 2013 1:05 pm

meemoe_uk says November 29, 2013 at 12:25 pm

The great man was right. Now the EU community recognizes there [sic; should be “their” I am assuming] importance.

No wonder viewpoints expressed contained such artful twists; logical thought would seem to be out-of-reach.
BTW, there are variety of observations that could be made to support your ‘contention’ of an ‘Electric universe’, but without a basis in logos and a grounding in science “cheerleaders’ are able to do no more than ‘lead cheers’ and wait a real physicist (an experimental physicist) to make those observations (NOT forthcoming, however, since a negative can’t be proven) for you. The sad part is, you probably have NO idea what those ‘observations’ might entail …
Cheer on then; “Party on Garth!”
.

meemoe_uk
November 29, 2013 1:17 pm

Wow I’ve had a good 2 days. 1st man on the planet to assert Ison alive and well + I’ve collected 2 scalps, one of them a follower, the other one one of the final bosses – Leif! Think thats the 1st time I’ve defeated Leif in technical argument combat.
Here’s there capitulation statements. I collect them as prizes . 8)
Leif Real science has moved on and it seems that the EU is stuck. Nothing you have said makes any sense, but this is nothing new.
JimHand-waving and filibustering; you have made not any technical points that will withstand serious cross examination.

November 29, 2013 1:22 pm

meemoe_uk says:
November 29, 2013 at 1:17 pm
Here’s there capitulation statements.
Unfortunately for your inflated ego, the two statements still hold. The DK-effect comes to mind:
“The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than is accurate. This bias is attributed to a metacognitive inability of the unskilled to recognize their ineptitude.”
http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
But despair not, you are joined in company by many others of many stripes.

November 29, 2013 1:25 pm

John Day says November 29, 2013 at 12:09 pm

What facts?

Then, there lies the problem …
To paraphrase Arthur Laffer: “If you treat all your constants as variables then your thinking is bound to be screwed up.”
.

Jurgen
November 29, 2013 1:38 pm

See – owe to Rich says:
November 29, 2013 at 8:49 am
Was it electrical? How could anything mechanical or thermodynamic explain the extreme rapidity?

Regarding the dissipation of the comet’s substance.
I am still thinking all the time: maybe no dissipation, but coincidence with a CME.
There were several CME’s going on before and after (my layman’s interpretation of the video’s), so the chance for a coincidence was there.
I am not into EU, but I was thinking about the “poof” Anthony talks about: this is very strange, this massive “poof” is completely different from the comets trajectory as if it had no momentum at all, whereas this “poof” has the same direction and speed a CME would have (again: to my layman’s eyes).

u.k.(us)
November 29, 2013 1:53 pm

lsvalgaard says:
November 29, 2013 at 1:22 pm
““The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than is accurate. This bias is attributed to a metacognitive inability of the unskilled to recognize their ineptitude.”
=================
And I always thought my ineptitude was due to being inept.
This opens up whole new world’s to explore !!

November 29, 2013 1:56 pm

u.k.(us) says:
November 29, 2013 at 1:53 pm
“I always thought my ineptitude was due to being inept.
This opens up whole new world’s to explore !!
and scalps and prizes to collect and to enjoy the pleasantries of pseudo-science.

November 29, 2013 1:57 pm

Question: Looking to the SOHO coronagraph movie (in blue) one sees two tails: a sharp narrow tail above and a tail spreading out below. According to Phil Plait, http://www.slate.com/blogs/bad_astronomy/2013/11/27/comet_ison_still_alive.html, the ion tail is above (narrow tail) and the dust tail is underneath (spreading out). Is he right?
I thought it was the opposite. The dust tail follows the path of the comet head and the ion tail is blown back by the solar wind.

November 29, 2013 2:02 pm

rikgheysens says:
November 29, 2013 at 1:57 pm
Is he right? I thought it was the opposite. The dust tail follows the path of the comet head and the ion tail is blown back by the solar wind.
He is right. But very close to the Sun where the speed is so high, the dust tends to ‘lag’ a bit so the dust tail makes an angle to the orbit.

November 29, 2013 2:07 pm

Leif, The Universe is made of Electric, No Leif shut up and listen, meemoe_uk asserted that the comet survived the swing around the sun using near real-time observations, obviously this is solid proof of the Electric Universe theory, you know… that whole connection between meemoe_uk and comets. /jk

Darren
November 29, 2013 2:30 pm

Any object that has been in deep space for 4.6 Billion yEars will accumulate alot of ice and like your freezer accumulates ice over time. still hope myself i think alot of people wont see it due to chemtrails

meemoe_uk
November 29, 2013 2:33 pm

Ok, onto the tails…
Is it only me in the whole world that can spot this one? or only me on WUWT?
leif said : ” A comet has three tails: an ion tail and two dust tails. The latter lie along the orbit and the former is directed away from the sun. So close to the sun there can be, and often is, a large angle between the two. This is quite normal and nothing special. ”
But the new tail on Ison right now aligns neither with the orbit nor radially from the sun. So the conventional theory has failed.
What say ye Leif? Need my explanation?, or can you wriggle out of this one yourself? Note that ‘dust tail lagging a bit’ doesn’t explain what were seeing right now.

meemoe_uk
November 29, 2013 2:39 pm

I am not into EU, but I was thinking about the “poof” Anthony talks about: this is very strange, this massive “poof” is completely different from the comets trajectory as if it had no momentum at all, whereas this “poof” has the same direction and speed a CME would have
That was the Comet’s debye shield being popped, which released all its plasma in its corona. Of course plasma is so spare that once it is free it is blown around effortlessly by any force.
Also the electric discharge may have atomized some of the comets rocky surface into a vapour.

November 29, 2013 2:42 pm

Jim G says:
November 29, 2013 at 7:54 am
Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force
I would hardly call it a hard turn since for all intents and purposes, from a kilometre before to a kilometre after perihelion, it went in a straight line. However there was no net force right at perihelion since the centripetal force, given by F = mv^2/r was balanced by the gravitational force from the sun, given by F = GMm/r^2.

u.k.(us)
November 29, 2013 2:44 pm

lsvalgaard says:
November 29, 2013 at 1:56 pm
“and scalps and prizes to collect and to enjoy the pleasantries of pseudo-science.”
==============
Yep.

November 29, 2013 2:45 pm

meemoe_uk says:
November 29, 2013 at 2:33 pm
But the new tail on Ison right now aligns neither with the orbit nor radially from the sun. So the conventional theory has failed.
Nonsense, conventional theory explains things quite well:
“The dust tail consists of dust particles that have been pushed out of the coma by radiation pressure from the sun. Compared to the ION tail, the dust tail is morphologically diffuse, and appears white or slightly pink (because the dust grains reflect sunlight slightly better at longer wavelengths than at shorter wavelengths). The dust particles in the tail are individually in orbit about the sun, each with slightly less attraction to the sun than the nucleus because of the effect of radiation pressure. This causes the dust tail to be curved as the comet swings around the sun.”

November 29, 2013 2:48 pm

John Day says November 29, 2013 at 12:09 pm
What facts?
@_Jim
Then, there lies the problem …

Yes, you are the problem. I see how you operate. You’re acting like a troll, who lurks around these discussions, waiting to insert some seeming intelligent comments. But if the subject matter is beyond your expertise, you fake a response by Googling some stuff and throw it out, hoping it will sound intelligent.
If some one disputes your input, then you try to blame them for failing to understand, or similar subterfuge to place the onus back on them.
You’ve done this several times with me over the past day or two. Now I see you playing the same gambit with meemoe_uk. But he can also see you have no real expertise, beyond trivial Googling. You really don’t understand the problems we’re talking about.
You reap what you sow.
😐

French_Atkins
November 29, 2013 3:06 pm

u.k.(us) says:
November 29, 2013 at 12:53 pm
French_Atkins says:
November 29, 2013 at 12:33 pm
lsvalgaard says:
November 29, 2013 at 12:08 pm
French_Atkins says:
November 29, 2013 at 12:06 pm
GAME OVER
You throwing in the towel is accepted. Have a nice day.
Thanks, you too. And whatever you do, please don’t stop throwing out your proverbs, poetry, pleonasms and platitudes. It makes a nice change from serious science.
++++++++++++++++
And just where do you think this comment might take you ?, back into the realm of science ?,you didn’t present any.
You’ve presumably skipped quite a few posts… One or two quotes from my previous posts, in which I refer to the OBSERVATIONAL EVIDENCE which I take to be the ONLY legitimate basis for any SCIENTIFIC THEORY:
French_Atkins says:
November 29, 2013 at 3:29 am
[…]
“The case is clear: Ison, like the four comet nuclei we have so far actually managed to image from pretty close-up, is not a “dirty iceball” but a big lump of solid rock, which displayed intense discharge phenomena with build-up of increasing voltage difference as it moved rapidly towards the positively charged sun. It seems, as meemoe_uk suggests, that “when ISON flew into the CME it earthed its voltage ( or Suned it ), so the glowing stopped”, a phenomenon which is totally in accordance with the expectations of EU theory but totally inexplicable by mainstream, gravity-only Big Bang theory.” (unless, of course, the glowing stopped because ISON had been destroyed, which is clearly not the case…)
[…]
French_Atkins says:
November 29, 2013 at 10:44 am
lsvalgaard says:
November 29, 2013 at 9:36 am
French_Atkins says:
November 29, 2013 at 9:33 am
Glad anyway that you have nothing to say about the substance of my posts.
“There is nothing to say because there is no substance.
If you need a general refutation of EU, this link is a good place to start:http://dealingwithcreationisminastronomy.blogspot.com/p/challenges-for-electric-universe.html”
I have nothing against a site which, on the face of it, combats creationist ideas in astronomy, quite the contrary in fact: one of the reasons why I turned away some years ago from the Big Bang theory was precisely that it is the BB which enshrines the ULTIMATE creationist theory. EU theory, on the other hand has absolutely NOTHING to say about the nature or the time of the origin of the Universe. This is already a huge step forward in scientific thinking: I’m not saying I don’t believe in a possible Initial Creation, but simply that we can obviously know nothing about it, as Big Bangers claim we can.
Apart from that, I don’t need a refutation of EU, because it proceeds from correct scientific method in that it is evidence-based, in the same way that climate skepticism is evidence-based. I went down the same intellectual path in moving from Big Bang to EU theory as I did a year or so later in switching from the warmist camp to the climate-skeptic camp, once I had realized that the same forms of obfuscation were being practiced in both so-called “sciences”. Elegant maths and computer models can do nothing in the face of hard, irrefutable, observational evidence, whatever the field under study.
Do I need to repeat that like many other “skeptics”, the reason for my abandoning the mainstream, Establishment positions I previously held for many years (both in cosmology and in climate “science”) was the realization that the paradigm being presented by the Establishment was falsified by every new piece of observational evidence and that the scientific method was being travestied (sorry, Mr. Trenberth…). It then just becomes a matter of intellectual honesty: personally, I’m in the fortunate position of not depending for my livelihood on any sort of university or institutional funding in these areas so I don’t need to compromise on anything.
You had your dictionary opened to the “p” section, by the looks of your comment ?
No, I know precisely why I wrote those four “p” words and can quote the passage(s) in Mister lsvalgaard’s posts which each one refers to:
-“proverb”: “There is nothing wrong with ignorance. Willful ignorance, on the other hand, is an abomination.” (Posted November 29, 2013 at 9:11 am)
-“poetry” (or “hand-waving”): “Don’t you see that by willfully wearing blinkers you are missing the glorious picture of where and when we came from that we have teased out of the wonderfully precise observations of the past ten years? (Posted November 29, 2013 at 10:55 am)
– pleonasm (in the sense of circular, self-proving reasoning but nothing else): “On a technical point: there was no plasma in the Universe starting about 380,000 after the BB and for the next several hundred millions years, at which time gravity had caused the first stars to form and by their UV radiation ionize the intergalactic medium. What does that fact do to EU theory?» (Posted November 29, 2013 at 10:55 am)
– platitude: “throwing in the towel” (among others…) (posted November 29, 2013 at 12:08 pm)
For my part, I will gladly assume responsibility for a fifth “p” word: the PREDICTION which I made in my post of November 29, 2013 at 3:29 am:
“Now that this big lump of rock has emerged on the other side with a fantastic gravity assist and a speed still in excess of 600,000 mph, the charge difference will once again increase very rapidly, the arc-mode discharge phenomenon will probably resume even more powerfully and we are likely to see a truly Great Comet over the coming weeks. But NOT for the “reasons” put forward by mainstream astronomy….” Indeed, since the mainstream astronomers, with all their “dirty snowball” preconceptions, were announcing the premature demise of ISON as having “fizzled out” or having been destroyed during perihelion, I don’t see how on earth they’re going to account for (and even have the cheek to attempt to account for) a possible display of a Great Comet in the coming days and weeks which, since all the “ice” they still conceptually hang on to must have been completely boiled away, could thus only be the result of electric discharge phenomena.

meemoe_uk
November 29, 2013 3:10 pm

Leif says This causes the dust tail to be curved as the comet swings around the sun.”
It’s not the ‘dust’ tail that’s the prob. The ‘dust’ tail is in the right place.
It’s ‘the’ ion tail. It’s been about 45 to 90 deg out of radial alignment since it appeared on LASCO C3.

J. Sperry
November 29, 2013 3:19 pm

“Wikipedia has a good article on that http://en.wikipedia.org/wiki/Roche_limit but the table for selected examples is wrong [the unit should be km not meter].”
I fixed it for you.

November 29, 2013 3:25 pm

Is the orientation of the comet magnetic in nature? and could the magnetic orientation of the comet’s nucleus be the cause of the shape and size of the comets tail? My thinking is, if the comet is magnetic in nature and one side of its nucleus is naturally attracted to the sun as it progresses along its trajectory, as it approached aphelion the turbulence from solar winds may have knocked the nucleus off this magnetic orientation, resulting in the reduction in the formation of the comets tail as-well as the solar wind dispersing it, so, as the comet rights its magnetic orientation and realigns its natural magnetic polarities with the sun, we should begin to see it brighten up and form its tail again.

November 29, 2013 3:27 pm

French_Atkins says:
November 29, 2013 at 3:06 pm
the OBSERVATIONAL EVIDENCE which I take to be the ONLY legitimate basis for any SCIENTIFIC THEORY
Current astrophysical theory is firmly based on observational evidence. On ALL of the evidence.
meemoe_uk says:
November 29, 2013 at 3:10 pm
It’s ‘the’ ion tail. It’s been about 45 to 90 deg out of radial alignment since it appeared on LASCO C3.
There are such things as perspective and projection…
J. Sperry says:
November 29, 2013 at 3:19 pm
I fixed it for you.
For ‘us’. Thanks.

November 29, 2013 3:33 pm

Sparks says:
November 29, 2013 at 3:25 pm
Is the orientation of the comet magnetic in nature? and could the magnetic orientation of the comet’s nucleus be the cause of the shape and size of the comets tail?
No, that is not the way it works. But the solar wind is magnetic and as it and the comet meet the magnetic field is ‘draped’ around the comet. If the magnetic field in the solar wind changes direction, e.g. switches polarity as a current sheet is passing the comet, the solar wind will steal the tail. Another one grows out rapidly. http://science1.nasa.gov/science-news/science-at-nasa/2007/01oct_encke/

November 29, 2013 3:40 pm

meemoe_uk says:
November 29, 2013 at 3:10 pm
It’s ‘the’ ion tail. It’s been about 45 to 90 deg out of radial alignment since it appeared on LASCO C3.
There are such things as perspective and projection…
Not to speak about aberration: since the tail ions move away at 300 km/s and and comet is also moving at 300 km/s, the tail will be at a 45 degree angle…
http://www.spacetimetravel.org/aur/node3.html

u.k.(us)
November 29, 2013 3:41 pm

French_Atkins says:
November 29, 2013 at 3:06 pm
===============
Darn, I should just keep my mouth shut.
That’s no fun 🙂

Carla
November 29, 2013 3:55 pm

http://www.spaceweather.com has an update and a good video recommendation..
“””Before the flyby, experts had made many predictions about what might happen to the comet, ranging from utter disintegration to glorious survival. No one predicted both.
Karl Battams of NASA’s Comet ISON Observing Campaign says, “[colleague] Matthew Knight and I are ripping our hair out right now as we know that so many people in the public, the media and in science teams want to know what’s happened. We’d love to know that too! Right now, here’s our working hypothesis:
“As comet ISON plunged towards to the Sun, it began to fall apart, losing not giant fragments but at least a lot of reasonably sized chunks. There’s evidence of very large dust in the long thin tail we saw in the [SOHO coronagraph] images. Then, as ISON plunged through the corona, it continued to fall apart and vaporize, losing its coma and tail completely just like sungrazing Comet Lovejoy did in 2011. What emerged from the Sun was a small but perhaps somewhat coherent nucleus that has resumed emitting dust and gas for at least the time being.”
Battams emphasizes that it is too soon to tell how big the remnant nucleus is or how bright the resurgent comet will ultimately become. “We have a whole new set of unknowns, and this ridiculous, crazy, dynamic and unpredictable object continues to amaze, astound and confuse us to no end. We ask that you please be patient with us for a couple of days as we analyze the data and try to work out what is happening.”
Astrophotographer Babak Tafreshi has edited an HD video (

)
that compares views of ISON from both of SOHO’s coronagraphs. “It seems the comet could become a naked eye object with several degrees of scattered tail by Dec 2nd or 3rd,” he predicts…”””

Bill Jamison
November 29, 2013 3:58 pm

The rest of Babak Tafreshi’s comment:
“It seems the comet could become a naked eye object with several degrees of scattered tail by Dec 2nd or 3rd,” he predicts. “It’s not the comet of the century for sure, and fainter than the Lovejoy sungrazer in Dec. 2011, but an interesting imaging target is just a few nights away!”
I hope he’s right about it being at least bright enough to be naked eye visible and a beautiful long tail would be nice. I’m hoping to get some pics of it next week.

French_Atkins
November 29, 2013 4:15 pm

lsvalgaard says:
November 29, 2013 at 3:27 pm
“Current astrophysical theory is firmly based on observational evidence. On ALL of the evidence.”
In that case, why does every new observation (of comets, of course but of virtually every other heavenly object or phenomenon too) invariably elicit comments from astronomers and science writers whose allegiance to the MS is never in doubt such as:
“This is a surprising/amazing/ extraordinary finding” (translate: “the theory is completely at a loss to account for it”)
“We still have much to learn about xxxx” (translate: “We still haven’t got the faintest clue about…”)
“The theory on xxxx may need to be further revised” (translate: “The theory on xxxx has just been falsified, again, but we’re going to fix it…”)
“Scientists say they need to carry out more research to fully understand…” (no translation needed)
Etc. etc.
As an immediate example, just watch the upcoming reporting of the ISON enigma, everyone, and make up your own minds whether, as in climate matters, the so-called experts are so sure that the “science is settled”…!

November 29, 2013 4:23 pm

I have done a recent post on some of the lame Electric Comet claims.
http://dealingwithcreationisminastronomy.blogspot.com/2013/11/electric-comets-failures-of-electric.html
A commenter has added some additional info of how we actually know how charges behave in space.
BTW, the recent LASCO view of ISON is consistent with the tail roughly along the Earth-Sun line after perihelion.

French_Atkins
November 29, 2013 4:23 pm

Carla says:
November 29, 2013 at 3:55 pm
“Battams emphasizes that it is too soon to tell how big the remnant nucleus is or how bright the resurgent comet will ultimately become. “We have a whole new set of unknowns, and this ridiculous, crazy, dynamic and unpredictable object continues to amaze, astound and confuse us to no end. We ask that you please be patient with us for a couple of days as we analyze the data and try to work out what is happening.”
Nufsaid already, methinks. No translation necessary. Where is the “theory firmly based on observational evidence”?

u.k.(us)
November 29, 2013 4:25 pm

French_Atkins says:
November 29, 2013 at 4:15 pm
=================
If you are gonna do it, call it what it is.
Monday morning quarterbacking.

meemoe_uk
November 29, 2013 4:38 pm

There are such things as perspective and projection…
Not to speak about aberration: since the tail ions move away at 300 km/s and and comet is also moving at 300 km/s, the tail will be at a 45 degree angle…

If these factors were knocking ‘the’ ion tail out of solar radial alignment by 90 degrees from our point of view they would be also doing something similar to the ‘dust’ tail. But they aren’t. The dust tail is acting like there’s no 3D view motion tricks.
And also perspective and projection can’t cause such distortions of view.
u linked to a special relativity page, which isn’t relevant to ison kinematics,.
Good grief Leif, you can get away with and hide behind a lot of astrophysical technical talk on WUWT, but I pushed u into the realm of 3D perspective, of which everyone can claim to have good intuition. As long as people know what radial alignment should look like they can see ‘the’ ion tail just hasn’t pointed in the right direction.

Jim G
November 29, 2013 4:41 pm

wbrozek says:
November 29, 2013 at 2:42 pm
Jim G says:
November 29, 2013 at 7:54 am
Hard to conceptualize that a body making a hard turn at 800,000 mph feels no force
“I would hardly call it a hard turn since for all intents and purposes, from a kilometre before to a kilometre after perihelion, it went in a straight line. However there was no net force right at perihelion since the centripetal force, given by F = mv^2/r was balanced by the gravitational force from the sun, given by F = GMm/r^2.”
Read ALL of what I said. There was no turn. Things travel in a straight line in curved space when in the presence of mass. Mass curves space.

Tom in Florida
November 29, 2013 4:45 pm

And to think for several days I have been lamenting that there have not been any lively solar discussions of late. Thanks to all.

Jim G
November 29, 2013 4:55 pm

John Day says:
November 29, 2013 at 10:15 am
@Jim G
>That is why I said to think of it as curved space, NOT a force! Read what I said.
“I did.
Somehow you think the notion of ‘curved space’ is necessary to understand gravitional mechanics. It’s not. Newton conceived all of this (including orbiting satellites in free fall) without having any idea of space-time curvature. ”
It is not a matter of how one thinks of it but rather how it is best approximated. Newtonian physics does not properly predict the observed orbit of Mercury, relativity does it much better.

Jurgen
November 29, 2013 4:58 pm

meemoe_uk says:
November 29, 2013 at 2:39 pm
That was the Comet’s debye shield being popped, which released all its plasma in its corona. Of course plasma is so spare that once it is free it is blown around effortlessly by any force.
Also the electric discharge may have atomized some of the comets rocky surface into a vapour.

Thanks for your reaction, but I still have my doubts. If it was just the comet’s plasma, that would not be much substance (“spare” as you say) and doesn’t explain the big “poof”. If it was atomized matter, it’s mass would retain the momentum of the comet resulting in a forward tilted “poof” which I didn’t see.
So I am still stuck with the idea of a coincidental CME.

u.k.(us)
November 29, 2013 5:00 pm

Jim G says:
November 29, 2013 at 4:41 pm
“Read ALL of what I said. There was no turn. Things travel in a straight line in curved space when in the presence of mass. Mass curves space.”
=====================
Seems to make sense.
Did it survive its passage ? The comet ?

meemoe_uk
November 29, 2013 5:08 pm

If it was just the comet’s plasma, that would not be much substance (“spare” as you say) and doesn’t explain the big “poof”. If it was atomized matter, it’s mass would retain the momentum of the comet resulting in a forward tilted “poof” which I didn’t see.
Ok, it was the debye shield popping AND the momentum of the CME. the CME has a lot of KE and would disperse the comets coronal+tail plasma, while the plasma had some glow left to make the poof more visible.
The atomized dust doesn’t need much consideration.

November 29, 2013 5:35 pm

By the hammer of Thor, is there really an outbreak of EU infection here?
There is no use trying to argue with them, they happily pick and choose things from the real world, ignore what we know about them, and then start screaming “ELECTRICITY DID IT” until you wish you could make a more Edison-like use of it and treat them like one of the poor animals he electrocuted.

November 29, 2013 5:53 pm

French_Atkins says:
November 29, 2013 at 4:15 pm
In that case, why does every new observation (of comets, of course but of virtually every other heavenly object or phenomenon too) invariably elicit comments from astronomers and science writers whose allegiance to the MS is never in doubt such as:
“This is a surprising/amazing/ extraordinary finding”
Funding, my dear boy. Funding. And there is something to learn from amazing things. Of course, the EU cult already knows everything, so nothing is amazing to them and they don’t learn.
meemoe_uk says:
November 29, 2013 at 4:38 pm
The dust tail is acting like there’s no 3D view motion tricks
The dust tail(s) act differently from the ion tail for well-understood reasons. This whole subject has been understood for at least half a century.
u linked to a special relativity page, which isn’t relevant to ison kinematics,.
If you would care to look: http://www.spacetimetravel.org/aur/node3.html Figure 8 illustrates aberration.
As long as people know what radial alignment should look like they can see ‘the’ ion tail just hasn’t pointed in the right direction.
But you apparently don’t know.

Carla
November 29, 2013 5:55 pm

French_Atkins says:
November 29, 2013 at 4:23 pm
Carla says:
November 29, 2013 at 3:55 pm
“Battams emphasizes that it is too soon to tell how big the remnant nucleus is or how bright the resurgent comet will ultimately become. “We have a whole new set of unknowns, and this ridiculous, crazy, dynamic and unpredictable object continues to amaze, astound and confuse us to no end. We ask that you please be patient with us for a couple of days as we analyze the data and try to work out what is happening.”
Nufsaid already, methinks. No translation necessary. Where is the “theory firmly based on observational evidence”?
————————–
Theory.. IMHO…is in a constant state of flux..as in fluxuations…
The understanding of our solar astrosphere from Oort Cloud to solar disk is still evolving. Comet Lovejoy (Dec. 2011) and now ISON, are game changers as they blew the minds of lots of physicists around the world…We may have to change our understanding about somethings..ya think? Lovejoy emerged like it was boingking its way back forth between field lines. woweee..

November 29, 2013 6:23 pm

Max™ says @ November 29, 2013 at 5:35 pm
“By the hammer of Thor, is there really an outbreak of EU infection here?”
It is being contained rather effectively, but I get the feeling that the practitioners are completely unaware that they have been thoroughly fisked, again. I have dubbed the two of them: Captain Pompous and his Self-Winding Lackey.
Made my Mrs giggle uncontrollably for a spell.

Carlo
November 29, 2013 6:53 pm

ISON flies near the sun and there is an Sun Pole Reversal.
.

Jurgen
November 29, 2013 6:57 pm

However much I love the fireworks and the title of this thread, looking at the video’s and images again and seeing other video’s with no “poof” when Ison gets to the black disk of the camera, I conclude there was no “poof” dissipating (parts of) Ison, it was the “loop trick” of the video.
As already indicated:
Gijs says:
November 28, 2013 at 1:09 pm
The CME isn’t the reaction of the nearby coming comet, it’s at the beginning of the sequence, at the start point of the movie where the comet is coming into picture at right. Butt still a magnificent sight!

u.k.(us)
November 29, 2013 7:29 pm

Jurgen says:
November 29, 2013 at 6:57 pm
===============
Glad you viewed it, fresh eyes.

November 29, 2013 9:19 pm

This looks like a good place to ask dumb questions: could the material from the CME have protected ISON in any way? Could it have obscured the observations? …and the wildest of all – could some of that CME material have altered/enhanced the nucleus? My best guess is no, yes, and no.

littlepeaks
November 29, 2013 9:52 pm

By calculating the velocity and direction of the remnant, and comparing that with the expected velocity and direction that was originally forecast for the comet, would it be possible to calculate the ratio of the mass of the remnant to the comet’s original mass?

November 29, 2013 10:04 pm

littlepeaks says:
November 29, 2013 at 9:52 pm
By calculating the velocity and direction of the remnant, and comparing that with the expected velocity and direction that was originally forecast for the comet, would it be possible to calculate the ratio of the mass of the remnant to the comet’s original mass?
No, as we don’t know the force of the out-gassing jets. http://www.lpl.arizona.edu/~yelle/eprints/Yelle04a.pdf

See - owe to Rich
November 30, 2013 2:00 am

French_Atkins:

For my part, I will gladly assume responsibility for a fifth “p” word: the PREDICTION which I made in my post of November 29, 2013 at 3:29 am:
“Now that this big lump of rock has emerged on the other side with a fantastic gravity assist and a speed still in excess of 600,000 mph, the charge difference will once again increase very rapidly, the arc-mode discharge phenomenon will probably resume even more powerfully and we are likely to see a truly Great Comet over the coming weeks. But NOT for the “reasons” put forward by mainstream astronomy….” Indeed, since the mainstream astronomers, with all their “dirty snowball” preconceptions, were announcing the premature demise of ISON as having “fizzled out” or having been destroyed during perihelion, I don’t see how on earth they’re going to account for (and even have the cheek to attempt to account for) a possible display of a Great Comet in the coming days and weeks which, since all the “ice” they still conceptually hang on to must have been completely boiled away, could thus only be the result of electric discharge phenomena.

Well, it’s good to make predictions. At the moment Karl Battams at http://www.isoncampaign.org/karl/a-trail-of-questions says that ISON is magnitude +5 and fading, which isn’t going to make for a truly Great Comet nor even a naked eye one. But if your electrical theory is right, perhaps it will brighten again? And the mainstream astronomers have confessed they were wrong about the demise, so there still can be a significant nucleus (indeed, like meemoe_uk I think there must be) in which volatile materials could still reside having been protected by outer layers during perihelion.
Rich.

Sera
November 30, 2013 3:26 am

I would like to thank Leif for the work that he does. I would like to admonish him for acting like a child. Many of his comments violate blog policy and it pains me to read his puerile insults.
Just my opinion.

phlogiston
November 30, 2013 6:15 am

So let me get this straight: first comet Ison goes “poof”. Then it comes out?

Carla
November 30, 2013 6:24 am

As our knowledge evolves on sun “escaping” comets it spills over into magnetic fields of the lower corona of our sun.
Probing the Solar Magnetic Field with a Sun-Grazing Comet
Cooper Downs1,*, Jon A. Linker1, Zoran Mikić1, Pete Riley1,
Carolus J. Schrijver2, Pascal Saint-Hilaire3
On 15 and 16 December 2011, Sun-grazing comet C/2011 W3 (Lovejoy) passed deep within the solar corona, effectively probing a region that has never been visited by spacecraft. Imaged from multiple perspectives, extreme ultraviolet observations of Lovejoy’s tail showed substantial changes in direction, intensity, magnitude, and persistence. To understand this unique signature, we combined a state-of-the-art magnetohydrodynamic model of the solar corona and a model for the motion of emitting cometary tail ions in an embedded plasma.
The observed tail motions reveal the inhomogeneous magnetic field of the solar corona.
We show how these motions constrain field and plasma properties along the trajectory, and how they can be used to meaningfully distinguish between two classes of magnetic field models.
http://www.sciencemag.org/content/340/6137/1196.short
Lots of info available on the last comet to escape the LOWER solar corona which was Lovejoy in Dec. of 2011. (outgassing and tensile strength)

Carla
November 30, 2013 6:40 am

And size must also matter as to whether it escapes..
size and composition of the comet
amount of outgassing
tensile strength
direction of travel into the corona (neutral line?)
field foot points
lucky stiff if it doesn’t get hit by a CME or some other interaction region

DirkH
November 30, 2013 7:54 am

Max™ says:
November 29, 2013 at 5:35 pm
“By the hammer of Thor, is there really an outbreak of EU infection here?
There is no use trying to argue with them, they happily pick and choose things from the real world, ignore what we know about them, and then start screaming “ELECTRICITY DID IT” until you wish you could make a more Edison-like use of it and treat them like one of the poor animals he electrocuted.”
While scientists claim their model of comets as dirty snowballs is the real deal, they are constantly befuddled, amazed and baffled by what happens in the real world. LSvalgaard says they only pretend to be baffled for funding, in fact they knew all along what would happen due to their perfect theories.
So it’s a pity they cannot tell us what will happen before it happens because they need to lie for funding.
Given LSvalgaards admission of this strategy, I am more than willing to lend the EU people my ear, as they seem to be less corrupt.

Carla
November 30, 2013 7:58 am

“”The Great Comet of 1843 developed an extremely long
tail during and after its perihelion passage.
At over 2 Astronomical Units in length, it was the longest known cometary tail until measurements in 1996 showed that Comet Hyakutake’s tail was almost twice as long. There is a painting in the National Maritime Museum that was created by astronomer Charles Piazzi Smyth. The purpose of the painting is to show the overall brightness and size of the tail of the comet.””
http://en.wikipedia.org/wiki/Kreutz_Sungrazers
http://upload.wikimedia.org/wikipedia/commons/9/94/Great_Comet_of_1843.jpg

Carla
November 30, 2013 8:08 am

Well ya know, I had to find out what the heliospheric magnetic field strength was for 1843 after reading that little ditty on the “Great Comet of 1843.”
Now where might I find that information?..lol
Oh I know..lol
Page 30 of..
What Geomagnetism can Tell Us about the Solar Cycle?
Leif Svalgaard
Bern, 11 Nov., 2013
http://www.leif.org/research/What-Geomagnetism-can-Tell-Us-about-the-Solar-Cycle.pdf

Carla
November 30, 2013 8:11 am

Which now leads to..
Will we see more Kreutz family comets when the heliospheric magnetic field and cycle is at floor level?

November 30, 2013 8:15 am

Carla says:
November 30, 2013 at 8:11 am
Will we see more Kreutz family comets when the heliospheric magnetic field and cycle is at floor level?
Yet another puerile comment from me: no, as the magnetic field and cycle have nothing to do with comets coming and going.

Jurgen
November 30, 2013 8:55 am

Ruthless honesty is a necessary asset in science. This honesty may very well expand to social interaction, depending on the circumstances. That may look like being rude on the surface, but when it is done for the cause of science, and science is your real priority, you should have no difficulty in accepting it. Leif endures ad hominems towards himself patiently. There is a lesson here for some.

Pamela Gray
November 30, 2013 8:58 am

Pacman spits out the dot.

Pamela Gray
November 30, 2013 9:00 am

Jurgen: Big ditto. I MUCH prefer straightforward discussion. Leif is a master at it.

Tom in Florida
November 30, 2013 9:11 am

Sera says:
November 30, 2013 at 3:26 am
“I would like to thank Leif for the work that he does. I would like to admonish him for acting like a child. Many of his comments violate blog policy and it pains me to read his puerile insults.
Just my opinion.”
While I agree that Leif can be very blunt at times, I am sure that this stems from his countless hours on this blog dealing with the same faulty arguments by others (you all know the players), over and over and over again ad nausea.

Carla
November 30, 2013 9:31 am

sheeesh Dr. S.
“Your Momma don’t Dance.” Loggins and Messina
The next solar cycle 25 is going to be smaller than 24. We don’t even know what the effects of an even smaller heliosphere might bring. How many gravitational constants aren’t so constant.
There are consequences to/ from flux uations.
And the sun eats comets..chomp..chomp..another form of ‘A’ccretion. (the A word but again)
Apparently lots of them based on observations..

November 30, 2013 9:34 am

Carla says:
November 30, 2013 at 9:31 am
The next solar cycle 25 is going to be smaller than 24. We don’t even know what the effects of an even smaller heliosphere might bring.
sheeesh Carla. Comets don’t care about the heliosphere.

Carla
November 30, 2013 9:39 am

That the sun accretes more matter during minimum periods (focusing) and less during high activity periods, (de-focusing) well.
that is it for todays rant.
Off to morph in the Oort cloud to find some gravitational constants..lol

November 30, 2013 9:42 am

Carla says:
November 30, 2013 at 9:39 am
That the sun accretes more matter during minimum periods (focusing) and less during high activity periods, (de-focusing) well.
Is not relevant for comets coming and going.
that is it for todays rant.
perhaps a little less ranting would be welcome.

November 30, 2013 10:09 am

Leif,
The distance within which tidal breakup occurs is called the Roche-limit. Wikipedia has a good article on that http://en.wikipedia.org/wiki/Roche_limit but the table for selected examples is wrong [the unit should be km not meter]. Anyway, you can see that ISON is outside the Roche limit.
I assume that ISON was within the Roche limit at perihelion. For an average comet near the sun, a Roche-limit of 1,234,000 km is mentioned (for rigid bodies, see the website of wikipedia) while at perihelion, the comet was only 1,166,000 km above the solar surface. But it is unclear for me if with the formula “d = 1.26 R_M (…)” the Roche-limit ‘d’ starts from the center of the Sun or from the surface.
This webpage http://www.asterism.org/tutorials/tut25-1.htm is more clear, where ‘L_R’ (Roche-limit) starts obviously from the center. It is stated: “The Sun’s limit for comets is 2.4 million km”, i.e. from the center. At perihelion, the comet ISON was only 1,862,000 km away from the solar center.

November 30, 2013 10:14 am

Jim G says:
November 29, 2013 at 4:55 pm
John Day says:
November 29, 2013 at 10:15 am
@Jim G
> That is why I said to think of it as curved space, NOT a force! Read what I said.
“I did.
Somehow you think the notion of ‘curved space’ is necessary to understand gravitational mechanics. It’s not. Newton conceived all of this (including orbiting satellites in free fall) without having any idea of space-time curvature. ”
It is not a matter of how one thinks of it but rather how it is best approximated. Newtonian physics does not properly predict the observed orbit of Mercury, relativity does it much better.

You’re still not grasping the what I’m trying to tell you. Listen up, I’m trying to teach you something.
It doesn’t help to try to think of ordinary 3-D Euclidian space as “curved”. Einstein conceived that concept thinking in 4-dimensional Riemannian manifolds, where the 4th dimension is time.
It’s also not helpful to say that curved space should be used instead of forces. Or that Newtonian physics is wrong and should be replaced by “relativity”.
A better way to view this is to understand that in the General Relativity framework, forces are not needed to understand free-falling objects, because the theory integrates gravity into the concept of distance measuring (metric tensor) such that free-falling objects (such as nearly-destroyed comets orbiting away from the Sun) are merely taking the shortest possible distance from point A to point B, along geodesics, which _might_ look curved to us.
Or not. The other important concept of General Relativity is that it doesn’t destroy Newtonian Physics, but _preserves_ it as the limiting cases for spaces with weak gravity (“flat space”) or low speeds (non-relativistic). So if you’re not near some big chunk of mass or approaching the speed of light, Newtonian physics still works fine.
Newtonian physics got 12 astronauts to the Moon and back safely, so you really shouldn’t worry much about the anomaly in the precessing rate of Mercury’s perihelion which you said is fixed by relativity. The total error rate in that anomaly amounts to 43 arc-seconds per century. Big whoop. This anomaly is barely measurable in the other planets. Mercury has the “largest” only because it’s moving faster than the others.
😐

Paul Westhaver
November 30, 2013 10:16 am

Has the trajectory of the comet remnant altered from the trajectory of the original pathway to any measurable degree?

November 30, 2013 10:42 am

@me
> Newtonian physics got 12 astronauts to the Moon and back safely …
… and the 6 astronauts who piloted the Command Module around the moon. :-]

November 30, 2013 10:43 am

rikgheysens says:
November 30, 2013 at 10:09 am
But it is unclear for me if with the formula “d = 1.26 R_M (…)” the Roche-limit ‘d’ starts from the center of the Sun or from the surface.
From the center.
This webpage http://www.asterism.org/tutorials/tut25-1.htm is more clear, where ‘L_R’ (Roche-limit) starts obviously from the center.
The standard formula of the RL is RL=A (dSun/dComet)^(1/3) [in radii]. With density Sun dSun being 1.4 and density Comet dComet assumed to be 0.5, the formula becomes RL = A * 1.41 Rsun from the center or A* 0.41 Rsun from the surface. So, all depends on the constant A, which usually is taken as 1.26 for a rigid body. For a fluid [deformable] body A is larger, perhaps 2.4 or so [also dependent on the shape of the body]. So, a lot depends on whether the comet is deformable like a drop of water. A dirty snow ball or a rock really isn’t, and with that assumption ISON was outside the Roche-Limit. If it were inside it would likely break up into a series of pieces each of which would be a little comet, like Shoemaker-Levy: http://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9 and we would expect to see a ‘string of pearls’. So far we don’t see any [this may change] so my initial conclusion is that ISON was not tidally disrupted.

Fernando
November 30, 2013 11:08 am

Game over…..again???? [/sarc

Carla
November 30, 2013 11:18 am

lsvalgaard says:
November 30, 2013 at 9:34 am
___
Wonder how solar wind and heliospheric parameters might be effecting comets orbit or incidence rate and you know stuff.
Below an example from CHANDRA observations during min and max.
Like this..
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
..Bodewits et al. (2007) analyzed the X-ray spectra of all the comets, eight in total,
which were studied with the Chandra X-ray observatory in the period
2000 to 2006, covering the transition from solar maximum to solar minimum.
Figure 3a shows the (background subtracted raw) spectra of all
the comets, and Figs. 3b, c show at which ecliptic latitude and phase in the
solar cycle the spectra were observed. It is immediately obvious that there
are spectral differences.
In Fig. 3a, three spectral bands are indicated, dominated by
emission from (i) C V, CVI, NVI (‘C+N’), (ii) by OVII,
and (iii) by O VIII ions, and the spectra are arranged so that, from top to bottom,
flux is systematically shifted from lower to higher energy bands.
The quantitative results of the spectral fits clearly show that the flux in the C+N band
is anticorrelated to that in the O VIII band (Fig. 3d), indicating that the comets were
exposed to different solar wind conditions.
As can be seen in Figs. 3b and 3c, all the comets which were observed at high
latitudes happened to be there during solar maximum, when the equatorial solar wind
had expanded into these regions. This implies that, until 2006, Chandra had not observed
any comet exposed to the polar wind. This situation changed in October 2007, during solar
minimum, when the nucleus of comet 17P/Holmes experienced a spectacular outburst, which increased its dust and gas outflow and optical brightness by almost a million times
within hours, from under 17 mag to 3 mag, making it by far the optically brightest comet observable by Chandra since its launch. At the time, comet 17P/Holmes was located at a
sufficiently high heliographic latitude (19◦) to be exposed to the polar wind at solar minimum.
It was thus expected
that this comet would exhibit considerably different X-ray
properties, and in fact this was observed: 17P/Holmes became
the first comet where Chandra did not detect any significant X-ray emission at all
(Christian et al. 2010). The most likely explanation for this dramatic X-ray faintness is
that the polar wind was so diluted and its ionization so low that only very little X-ray flux
was generated by charge exchange at energies above ∼300 eV. An instrumental effect,
i.e., a loss of sensitivity, can definitively be ruled out, because only two months later,
another comet, 8P/Tuttle, was observed with Chandra, and this comet, at low latitude (3◦),
was clearly detected in X-rays (Christian et al. 2010).
While comets allow us to sample the solar wind heavy ion content at locations which are inaccessible by in-situ measurements…..

Fernando
November 30, 2013 11:24 am

COMET ISON DIES … AGAIN
http://spaceweather.com/

November 30, 2013 11:25 am

Carla says:
November 30, 2013 at 11:18 am
Wonder how solar wind and heliospheric parameters might be effecting comets orbit or incidence rate and you know stuff.
You can stop wondering, the heliosphere does not affect the orbit or incidence rate.
Below an example from CHANDRA observations during min and max.
This is just one of your usual irrelevant rants. It is true that the comets can teach us about the solar wind [which was in fact predicted by Biermann from the existence of comet ion tails], but that is not relevant for the orbits or coming and going of comets.