The Electric Comet theory

[solrey]

deirendopa,
If you call nearly 40 hours of sanding with 10 to go fun, yeah, it's reeeaaaallll fun.
Nah, I love it. Grandpa was a wood worker, it's in the blood.

Back OT. deirendopa said

The aspect that I am most curious about, now, is why comets? I mean, why do comets have comas (and tails), but other solar system bodies do not?

Ah, the inner planets do have "comas" (magnetosphere's) and tails.
Go here for a diagram. The article describes some of the data MESSENGER collected from Mercury, particularly the surface sputtering and magnetic tornado's, but it's the diagram I'd like to direct your attention to. The structure is very similar to the Earth's magnetosphere, Venus too, even Mars, albeit very weak...and comets as well. All of the inner planets also have "stringy tails" nearly stretching all the way to the next planets orbital distance. The inner planets aren't experiencing rapid changes in their electric environment like comets do, but they receive a steady flow of charged particles from the Sun nonetheless, so they just remain in a non-luminescent state. Essentially they receive a, mostly, steady discharge from the Sun.

nasa.gov/mission_pages/messenger/multimedia/magnetic_tornadoes.html

I only pointed out the magnetron glow discharge because that would be the type of discharge mostly experienced, I was merely identifying the specific type of discharge. The strength and enhancement of the magnetic field doesn't really matter, that will fluctuate somewhat anyway.
The glow doesn't have to be bright and blinding, it can be a soft, neon-like glow as well. So the effect of the glow from discharge may or may not be "washed out" by reflection.

tusenfem, I'm doing my best with the time I have, trying to describe a very complicated, multifaceted process, sorry if it's not quite adequate.

What the EM field data depicts is two "stacked" DL's with a ring current just inside the inner DL. The outer DL at R1, the inner DL at R2, the ring current is that 10,000 Km thick current layer 25,000 Km downstream of R2. Multiple DL's and/or ring currents are not uncommon. That data actually makes the case for the EC even stronger, imo.
The Earth has strong ring currents, the "radiation belts", comets ring currents, are much weaker so they don't produce radiation like the Earth's. I wouldn't be surprised, not saying there is for sure, if there were also a third DL within a few hundred Km of the surface, which wouldn't be detected anyways unless a probe passed within that distance. The DL's dissipate and moderate the discharge current impinging on the surface. There is still a voltage potential between the surface and DL's. Even on Earth, there is a voltage potential of 100v/m @ sea level, even though the measured current of "flux transfer events" into the magnetosphere are on the order of hundreds of thousands of volts.

I think I should clear up the apparent confusion of what a discharge is. It seems that some of you good folks are stuck on the dramatic arc/spark type of discharge. That's what most are familiar with. But a discharge can be slow and steady as well, typically considered an electric current...as in a battery. A battery discharges slowly producing a steady electric current. That's pretty much a comet, it's essentially like those new capacitor batteries being developed, discharging at a mostly steady rate, but capable of rapid discharge as well.

 

[tusenfem]

tusenfem, I'm doing my best with the time I have, trying to describe a very complicated, multifaceted process, sorry if it's not quite adequate.

What the EM field data depicts is two "stacked" DL's with a ring current just inside the inner DL. The outer DL at R1, the inner DL at R2, the ring current is that 10,000 Km thick current layer 25,000 Km downstream of R2. Multiple DL's and/or ring currents are not uncommon. That data actually makes the case for the EC even stronger, imo.
The Earth has strong ring currents, the "radiation belts", comets ring currents, are much weaker so they don't produce radiation like the Earth's. I wouldn't be surprised, not saying there is for sure, if there were also a third DL within a few hundred Km of the surface, which wouldn't be detected anyways unless a probe passed within that distance. The DL's dissipate and moderate the discharge current impinging on the surface. There is still a voltage potential between the surface and DL's. Even on Earth, there is a voltage potential of 100v/m @ sea level, even though the measured current of "flux transfer events" into the magnetosphere are on the order of hundreds of thousands of volts.

That does not make ANY sense at all in DL talk, stacked double layers do not have a strong electric field gradient in between them, see e.g. stairstep double layers, in which it is shown that strong voltage drops in a plasma column split itself up into several DLs.

Why not make a picture to explain it. What kind of double layers are there? the ones carrying a current or the one on the boundary of two different plasmas?

You cannot use the clear sky electric field of the Earth, because the atmosphere is a very good insulator, whereas at a comet there is a plasma. Apples and oranges. Lots of word but nothing substantial.

 

[solrey]

You cannot use the clear sky electric field of the Earth, because the atmosphere is a very good insulator, whereas at a comet there is a plasma. Apples and oranges. Lots of word but nothing substantial.

It's a valid comparison, actually, from the perspective of comparing how that voltage potential is transferred to the surface in vastly different environments. On Earth, the atmosphere provides enough insulation to prevent surface sputtering, erosion and cratering, while still holding a 100v/m potential. Mercury, with a much thinner, atmosphere, does experience sputtering and "flux transfer events" on the surface. The difference on a Comet, as you so astutely note, is that the "atmosphere" is a conductive plasma which allows the discharge current to focus, or impinge, on the surface, relatively unhindered, other than the dissipation provided by the DL's. The purpose of my comparisons is to demonstrate the same processes manifesting in three different ways, one mostly at "rest" (Earth), one in a non-luminous discharge state (Mercury), the last in the glow discharge state (comet). Deirendopa had asked why planets don't act like comets, and I was demonstrating that they do, just in a less energetic manner, therefore it's not obvious.

That does not make ANY sense at all in DL talk, stacked double layers do not have a strong electric field gradient in between them, see e.g. stairstep double layers, in which it is shown that strong voltage drops in a plasma column split itself up into several DLs.

Get ready, here comes "check"...

Nagendra Singh

Department of Electrical and Computer Engineering, and CSPAR, University of Alabama, Huntsville, Alabama, USA

Kalyan Arcot

Department of Electrical and Computer Engineering, and CSPAR, University of Alabama, Huntsville, Alabama, USA

B. E. Wells

Department of Electrical and Computer Engineering, and CSPAR, University of Alabama, Huntsville, Alabama, USA

Using a 2.5-D parallel particle-in-cell simulation of a plasma of long length parallel to an ambient magnetic field Bo, we study the processes involved in determining the distribution of an applied electric potential drop parallel to Bo. The simulated plasma consists of both hot and cold plasmas of the magnetospheric and ionospheric origins, respectively. The former plasma is at a higher positive potential with respect to the latter, and thus the simulation results are relevant to the auroral downward current regions. The parallel processing enables us to simulate a long system with the magnetic field-aligned dimension L z ∼ 8192 λ do, where λ do is the plasma Debye length. We find that when the initially empty simulation box accumulates sufficient plasma supplied from hot plasma from the top and cold plasma from the bottom, a density cavity forms at the interface between the hot and cold plasmas. A part of the applied potential drop occurs in the cavity as a double layer (DL), while the rest of it as ambipolar fields supported by the density gradient in the hot plasma density on the high-potential side (HPS) of the DL. The DL propagates upward. The HPS of the DL is rich in large-amplitude electron holes. At later times in the evolution of plasma and fields as the DL reaches the top boundary, we find that a major part of the applied potential is distributed over long distances giving only a weak ambipolar type of parallel electric fields. Then again the distributed potential evolves into localized potential drops like in a stack of multiple double layers. The double layers and associated cavities emerge from low-frequency and long-wavelength oscillations in the presence of very hot ions. Parallel currents in the plasma seem to be the only source of free energy for driving the oscillations. We report the evolution of the electron velocity distribution functions as the potential distribution evolves.

Received 8 July 2008; accepted 8 December 2008; published 19 March 2009.

Citation: Singh, N., K. Arcot, and B. E. Wells (2009), Parallel electric fields in mixing hot and cold plasmas in the auroral downward current region: Double layers and ambipolar fields, J. Geophys. Res., 114, A03209, doi:10.1029/2008JA013591.

So, it would be nice if an EC proponent would come with a real model.

...and "mate".

Next?

 

[solrey]

RealityCheck...Howdy

Didn't want to forget your question.

How does the EC idea explain that jets on the Tempel 1 nucleus are correlated with "bright spots" on the nucleus that are measured to be ice?

I think I mentioned previously, H₂O is an expected electro-chemical reaction by-product, CO2 as well, so when the discharge subsides, any of those gases present at that time, would condense on the surface as thin deposits of ice in the vicinity of discharge/reaction activity. Otherwise, during discharge reactions, the H₂O breaks down to OH in another reaction. I believe all they detected were three small patches of thin ice layers covering a mere .026% of the surface. That does fit this scenario. The previous discharge activity reinforces local crustal magnetic fields in those conductive areas of the surface so the next time around the new discharge events are more likely to occur in or around those same areas. It's pretty much expected that new discharge activity would happen where previous discharge events deposited thin layers of water and carbon dioxide ice.
It's electrostatic deposition, like powder coating or electroplating.
Etching and erosion are what we see as the most obvious aspect of discharge on comets, and the most discussed, but deposition occurs at times as well.
BTW, there are a number of alkaline, or base, minerals that will produce H₂O when reacting with an acid, the H⁺, in the solar plasma stream. The next reaction that would occur is when that water then reacts with free electrons, liberated from the surface, within the electric field of the discharge current. Mineral salts in the dust and flakes etched from the surface are probably involved in this reaction. The cathode reaction is:
2H₂O + 2e^- -> 2OH^- + H₂

The further from the nucleus, the OH^- ions pick up free electrons producing more neutral OH molecules with distance from the surface. I believe that is what has been detected.

 

[Reality Check]

Some comets that should be asteroids according to EC

EC universe: Rocky bodies that have an orbit with an eccentricity below a minimum value will be asteroids (not comets).

Real universe: There are bodies that have an orbit with an eccentricity below a minimum value that are comets.
Star with the observed main-belt comets with a minimum eccentricity of 0.1644 (133P/Elst-Pizarro).

The JPL Small-Body Database Browser has a search engine. This shows that there are 12 cataloged comets with an eccentricity < 0.17.

This is not as impressive a flaw in the EC idea as the 173,583 cataloged asteroids with an eccentricity > 0.17 that should be comets according to EC. The list does include the rather interesting comet 29P/Schwassmann-Wachmann whose variation in brightness is in itself a flaw in EC.

 

[Reality Check]

RealityCheck...Howdy

Didn't want to forget your question.
...snip...

solrey...Howdy
Pretty much what I expected - assertions but not much science . Can you give citations to the papers that show that the "discharges" produce water from cometary rock?

The scenerio also fits the really simple science of water already being present.

But let us accept that there is something (EDM/coronal discharges/DL discharges/pixies?/etc.) creating water from rock. This leads to a really easy to answer question - how can we detect this sometihng?

• Does it produce X-rays?
  (Electric Comets III: No EU X-rays)
• Does it produce jets?
  (The EC assumption of EDM machining does not produce jets)
• Where are the coomponents of the process?
  (EDM in the EC idea needs a dielectric material which does not exist!)
• Is this something visble?
  (No EDM sparks are seen in images of comet nuclei.)
• How does this something work without heating up the surface?
  (No EDM hot spots are seen in thermal maps of Tempel 1.)

So far we have a something that is invisible in the spectra that comet nuclei have been observed in.

 

[Reality Check]

Is there an EC explantion for the birghtness changes in 29P/Schwassmann-Wachmann

Another problem with EC's basically external mechanism for the creation of the cometary coma and tail is that it means that it probably cannot account for sudden changes in comet brightness.
I would be interested in citations to the actual theory that accounts for this (even to a certain book advertisement site).

29P/Schwassmann-Wachmann

The comet is unusual in that while normally hovering at around 16th magnitude, it suddenly undergoes an outburst. This causes the comet to brighten by 1 to 4 magnitudes.[3] This happens with a frequency of 7.3 outbursts per year,[3] fading within a week or two. The magnitude of the comet has been known to vary from 19th magnitude to 9th magnitude, a ten thousand-fold increase in brightness, during its brightest outbursts. Highly changing surface processes are suspected to be responsible for the observed behavior.[3]

And from reference 3
"A continuous follow-up of Centaurs, and dormant comets: looking for cometary activity."

Such value is almost twice than the previously thought. SW1 outbursts are typically characterized by the sudden increase of 1 to 4 magnitudes in the brightness of the object. We have found no clear periodicity in the outburst production. Highly changing surface processes (perhaps associated with transition from amorphous to crystalline water ice) are suspected to be responsible for the observed behavior.

You may have access to this paper - Cometary outbursts - search of probable mechanisms - case of 29P/Schwassmann-Wachmann 1

Cometary outbursts, sudden increases in luminosity have not been clearly explained so far and their source is still a mystery. Various possible mechanisms as a source of cometary outbursts at large distances from the Sun have been considered. It has been stated that plausible mechanisms are the polymerization of HCN and the amorphous water ice transformation combined with electrostatic destruction of cometary grains in the head of the comet. The calculations have been carried out for a large range of cometary parameters and it has been shown that the proposed scenario of the outburst gives a jump in the comet brightness which is consistent with the real jump observed during the 29P/Schwassmann-Wachmann 1 outbursts.

 

[Reality Check]

Hi all. First post here. What fun, mind if I jump in?
First...EDM. EDM is the erosion or etching of an electrode. It could be a rapid, dramatic process, or a slow, steady process. Spark machining is used on very hard materials in industrial manufacturing processes. The slow erosion of the electrodes in a neon sign is a slower, less obvious form of EDM. We could say coronal discharge etching, but the electro-static potential may, at times, reach the threshold for arcing. We say EDM because there are multiple discharge levels occurring on comets, from electrostatic cleaning of dust, coronal discharge erosion, "magnetic vortex" etching, and possibly, infrequent arc machining.

I have to say that this is not made clear on a certain book advertisement web site.

Are you stating that there is no EDM machining and so "The observed jets of comets are electric arc discharges to the nucleus, producing “electrical discharge machining” (EDM) of the surface. The excavated material is accelerated into space along the jets’ observed filamentary arcs" is wrong?

If there is actual EDM machining then

• A dielectric material is needed so that sparks can form.
• The sparks will be visible.
• The sparks will produce X-rays in narrow bands and bursts.
• The surface of the comet nucleus will be heated by the machining and this will be visible (especially at the sites of jets).

 

[Reality Check]

Just noticed another "pretty pictures look alike and so the things in them are the same" fallacy on that book advertisement web site (in addition to comet nuclei look like asteroids) - Plasma Galaxies.
Someone should tell David Talbott and Wallace Thornhill that spiral galaxies are not actually spirals with nothing in between their arms (Anthony Peratt's Plasma Model of Galaxy Formation).

 

[DeiRenDopa]

There's a lot of stuff here solrey; so just a couple of points ...

[...]

Deirendopa had asked why planets don't act like comets, and I was demonstrating that they do, just in a less energetic manner, therefore it's not obvious.

Actually, I asked about other solar system bodies, which are far, far, far more numerous than planets: the natural satellites of the planets, asteroids, zodiacal dust, spaceprobes and rocket boosters (from Earth), ...

Also, I haven't been able to check properly, but it seems that the Earth's (and Jupiter's and Saturn's, and ...) magnetospheres are not at all like comets' comas (+/- tails) - for starters, there is no evidence of any DLs, as required by this EC idea - none of the asteroids which have been studied 'up close and personal' by spaceprobes (e.g. Ida, Eros, Mathilda, Steins) resemble comets, nor do any asteroids which have come close to Earth (quite a list!), nor do natural satellites such as the Moon, Deimos, and Phobos.

What quantitative studies have been done, to show that the data from spaceprobes which have gone past (or landed on) other solar system bodies is consistent with this EC idea?

Get ready, here comes "check"...






...and "mate".

Next?

I think this part of your post has to do with one of tusenfem's, but I can't see how it could possibly be considered as a real EC model; could you explain please?

 

[DeiRenDopa]

deirendopa,
If you call nearly 40 hours of sanding with 10 to go fun, yeah, it's reeeaaaallll fun.
Nah, I love it. Grandpa was a wood worker, it's in the blood.

Back OT. deirendopa said


Ah, the inner planets do have "comas" (magnetosphere's) and tails.
Go here for a diagram. The article describes some of the data MESSENGER collected from Mercury, particularly the surface sputtering and magnetic tornado's, but it's the diagram I'd like to direct your attention to. The structure is very similar to the Earth's magnetosphere, Venus too, even Mars, albeit very weak...and comets as well. All of the inner planets also have "stringy tails" nearly stretching all the way to the next planets orbital distance. The inner planets aren't experiencing rapid changes in their electric environment like comets do, but they receive a steady flow of charged particles from the Sun nonetheless, so they just remain in a non-luminescent state. Essentially they receive a, mostly, steady discharge from the Sun.

nasa.gov/mission_pages/messenger/multimedia/magnetic_tornadoes.html

I only pointed out the magnetron glow discharge because that would be the type of discharge mostly experienced, I was merely identifying the specific type of discharge. The strength and enhancement of the magnetic field doesn't really matter, that will fluctuate somewhat anyway.
The glow doesn't have to be bright and blinding, it can be a soft, neon-like glow as well. So the effect of the glow from discharge may or may not be "washed out" by reflection.

tusenfem, I'm doing my best with the time I have, trying to describe a very complicated, multifaceted process, sorry if it's not quite adequate.

What the EM field data depicts is two "stacked" DL's with a ring current just inside the inner DL. The outer DL at R1, the inner DL at R2, the ring current is that 10,000 Km thick current layer 25,000 Km downstream of R2. Multiple DL's and/or ring currents are not uncommon. That data actually makes the case for the EC even stronger, imo.
The Earth has strong ring currents, the "radiation belts", comets ring currents, are much weaker so they don't produce radiation like the Earth's. I wouldn't be surprised, not saying there is for sure, if there were also a third DL within a few hundred Km of the surface, which wouldn't be detected anyways unless a probe passed within that distance. The DL's dissipate and moderate the discharge current impinging on the surface. There is still a voltage potential between the surface and DL's. Even on Earth, there is a voltage potential of 100v/m @ sea level, even though the measured current of "flux transfer events" into the magnetosphere are on the order of hundreds of thousands of volts.

I think I should clear up the apparent confusion of what a discharge is. It seems that some of you good folks are stuck on the dramatic arc/spark type of discharge. That's what most are familiar with. But a discharge can be slow and steady as well, typically considered an electric current...as in a battery. A battery discharges slowly producing a steady electric current. That's pretty much a comet, it's essentially like those new capacitor batteries being developed, discharging at a mostly steady rate, but capable of rapid discharge as well.

(bold added)

My last post was in reply to the wrong one of yours solrey (sorry).

What does "The inner planets aren't experiencing rapid changes in their electric environment like comets do" mean? What changes in electric environment do comet experience (and how can one determine, or estimate, what such changes are)?

Also, what does "Essentially they [comets] receive a, mostly, steady discharge from the Sun" mean?

And it seems that you've removed (magnetron) glow discharge as a possible means of testing this EC idea ... if it can vary, be essentially undetectable (or not), is in any case not predictable, etc, etc, etc (or did I miss something important?).

Finally, I cannot see anything but a vague morphological similarity between comets' comas and planetary magnetospheres (i.e. they are both approximately spherical, circular in projection, with an extension in the anti-Sun direction). So can you please say more about the similarities you seem to see in them?

OK, one more: why don't the CLUSTER satellites have comas and tails?

 

[Reality Check]

Get ready, here comes "check"...

...and "mate".

Next?

Get ready, here comes "something unrelated to electric comets"...

Citation: Singh, N., K. Arcot, and B. E. Wells (2009), Parallel electric fields in mixing hot and cold plasmas in the auroral downward current region: Double layers and ambipolar fields, J. Geophys. Res., 114, A03209, doi:10.1029/2008JA013591.

...and "there it is"!

Magnetospheres produce auroras and require a body with a magnetic field. AFAIK comets do not have magnetic fields. They do not have magnetospheres. They do not have auroras.

 

[solrey]

Been a long day so I'll be brief.

RealityCheck, I suggest you go over my previous posts regarding the various types of discharge and why they are all considered an EDM process.

Also, note my comments about eccentricity. What you said about eccentricity relating to the EC model is absolutely incorrect. No one in the EC camp, that I'm aware of, has ever made such statements.

The answer about the magnetic field is the interplanetary magnetic field. The comet is immersed in it, it doesn't need to have it's own.

A word about magnetron glow discharge. The magnetic enhancement really only becomes important if the magnetic field increases sufficiently to initiate the discharge, while the voltage potential remains steady, primarily applicable to Main Belt Comets.

The abstract relating to auroral discharge was in response to tusenfem's statement that my description of the stacked DL's was incorrect. I posted that to demonstrate that my description is correct. The same plasma physics still apply, regardless of whether we're talking about auroras or comets.
According to what you said about the discharge physics, as applied to auroras, not having anything to do with comets, would be like saying our quantification of gravity on Earth does not apply to Mars as well.

All objects in the solar system are immersed in the interplanetary EM field. All of them have some level of voltage potential. Nearly all are in a "rest" state until such time as the EM environment produces an increased voltage potential that bumps the rest state up to the discharge mode.

 

[Reality Check]

RealityCheck, I suggest you go over my previous posts regarding the various types of discharge and why they are all considered an EDM process.

EDM has a specific meaning. i.e. electrical discharge machining.
The other types of discharge are not EDM.

Also, note my comments about eccentricity. What you said about eccentricity relating to the EC model is absolutely incorrect. No one in the EC camp, that I'm aware of, has ever made such statements.

What comments?
I am not claiming that anyone in the EC camp stated this. They are not the only people in the world who can think. It is a logical consequence of the fact that main-belt comets exist.

The answer about the magnetic field is the interplanetary magnetic field. The comet is immersed in it, it doesn't need to have it's own.

Ditto for every body in the solar system, e.g. asteroids, and we are back to the question of why every asteroid is not a comet.

The abstract relating to auroral discharge was in response to tusenfem's statement that my description of the stacked DL's was incorrect. I posted that to demonstrate that my description is correct. The same plasma physics still apply, regardless of whether we're talking about auroras or comets.

What you posted is that evidence that your description is correct for the auroral downward current region.
Now post your evidence that cometary coma are the same as the auroral downward current region.


I can think of a couple of differences:

• The Interplanetary Magnetic Field is 10^-9 tesla at the Earth - a factor of 10⁶ less than the Earth's magnetic field.
• The simulated plasma consists of both hot and cold plasmas of the magnetospheric and ionospheric origins, respectively.

All objects in the solar system are immersed in the interplanetary EM field. All of them have some level of voltage potential.

How big is this voltage potential?
I would say that eveything in the universe has "some level of voltage potential". The real question is that effect that has.

Nearly all are in a "rest" state until such time as the EM environment produces an increased voltage potential that bumps the rest state up to the discharge mode.

What is the amount of increase in voltage potential that bumps the "rest" state up to the discharge mode?

Citations?

 

[solrey]

Spark machining is a specific, controlled manufacturing process that utilizes the physics of electrode erosion to machine hard materials and is just one type of discharge within the category of EDM.

cadm.zut.edu.pl/pub/prawie%20wszystko%20o%20edm%20(ang).pdf

Four main types of steady or quasi-steady processes exist:
• the Townsend’s dark discharge, characterized by a very weak current (∼ 10−8 A);
• the glow discharge, widely used in many industrial processes, operating at low current (∼ 10−2 A), fairly high voltage (∼ 1 kV) and low pressure (∼ mbar). The glow plasma is weakly ionized and in a non-equilibrium state, and is visible as a uniform glowing column. As in the Townsend’s discharge, electrons are emitted by ion impacts on the cold cathode;
• the corona discharge, also at low current (∼ 10−6 A) but at atmospheric pressure. Corona discharges develop locally (typically around sharp ends of wires) in strongly non-uniform electric field;
• the arc discharge, characterized by high current (∼ 100 A), low voltage (∼ 10 V) and a bright light emission. The arc discharge differs from the glow discharge in the electron emission mechanism. In arcs, electrons are emitted by thermionic processes, due to the heating of the cathode. The plasma of high pressure arcs can be considered to be in a state of thermodynamic equilibrium.

The physics of the multiple stacked double layers are not limited to the downward auroral current. The proof that this applies to comets is in the following data.

Based upon the behavior of the electric fields and the cold electrons, three regions can be identified in the cometosheath (in particular during the Vega 1 approach): transition layers are passed through at ∼780,000 km (R 1) and ∼360,000 km (R 2). The outer cometosheath (near and beyond R 1) is characterized by large-scale variations in the cold electron density and the electric field, peaking at ∼1 mHz. The R 2 crossing is detected in the plasma wave data as enhanced fluctuations at ∼15 mHz. About 25,000 km downstream of R 2, the spacecraft traverses a current layer (thickness ∼10,000 km) indicated by a sharp gradient in the dc electric field and the cold electron density.

* The Interplanetary Magnetic Field is 10-9 tesla at the Earth - a factor of 106 less than the Earth's magnetic field.
* The simulated plasma consists of both hot and cold plasmas of the magnetospheric and ionospheric origins, respectively.

I don't recall them saying anything about magnetic field strength affecting the development of multiple double layers. That being said, I haven't seen the full paper with the equations to determine what effect changes in B would have. I believe the magnetic field merely acts to guide the direction of charged particle flow resulting in field aligned currents. The physics apply whether within Earth's magnetic field and magnetosphere/ionosphere ( stacked DL's also, btw ) , or a comets coma and the interplanetary magnetic field. Hot and cold plasmas apply to comets as well. The hot plasma is the solar plasma stream and the cold plasma is the ionized gas within the coma.

What is the amount of increase in voltage potential that bumps the "rest" state up to the discharge mode?

There are too many variables to be able to say, oh X-volts is all it takes. I won't even get into amperage right now, we'll just consider that it remains constant. Just to give you an idea, it could require an increase of, as low as <1v, or as high as >10,000v.

 

[tusenfem]

Get ready, here comes "check"...
...and "mate".

Next?

Not really:

Then again the distributed potential evolves into localized potential drops like in a stack of multiple double layers.

 

[solrey]

tusenfem, wassup?

OK, I'm a friendly guy so I'll concede to your position that my previous example of stacked double layers applies only to Earth's aurora as the abstract implies.

That's alright, I have backup.

While it doesn't mention comets, there is a list of literature on double layers, even a list on multiple double layers, at the end of the following presentation.
Multiple Double Layers in Laboratory Experiments Relevant for Space Plasma Phenomena.

phys.uit.no/IPELS05/Talks&posters/Monday/SchrittwieserIPELS%208%20InvLect.pps


Generation and Dynamics of Multiple Double Layers in Plasma.

epsppd.epfl.ch/Roma/pdf/P4_011.pdf

Whether you think they apply to comets or not, this has all been in reply to the following statement:

That does not make ANY sense at all in DL talk, stacked double layers do not have a strong electric field gradient in between them, see e.g. stairstep double layers, in which it is shown that strong voltage drops in a plasma column split itself up into several DLs.

Okeydokey:

Under certain experimental conditions, a more complex structure in form of two or more subsequent DLs was observed, called a multiple double layer (MDL). It appears as several bright and concentric plasma shells attached to the anode of a glow discharge or to a positively biased electrode immersed in plasma. The successive DLs are precisely located at the abrupt changes of luminosity between two adjacent plasma shells. The axial profile of the plasma potential has a stair step shape, with each potential drop being close to the ionization potential of the gas atoms. This kind of structure was recently called concentric multiple double layer.

 

[solrey]

I realize that my description of the stretched coma and tail, as well as the ionization sequence of OH^- was awkward, to say the least.
I'll try again.

First, the shells of the electro-magnetic environment are not to be confused with the visible dust shells which are the result of the off-gassing and dust from erosion being accelerated away from the points of discharge on the surface. Rotation of the comet swirls the stream around the nucleus as the outbound neg. ions in the coma mix with pos. ions moving towards the surface. The neg. ions give up electrons neutralizing the charge and decreasing the pos. potential of the highly ionized H⁺ ions that receive those electrons, on their way to electro-chemical reactions on, and near, the surface.
The solar plasma stream flows from the pos. potential at the Sun outward to the relatively neg. potential at the heliopause. The high velocity flow of strong pos. ionized particles drags the neg. and neutral atoms and molecules from the coma with them, while the voltage potential stretches the DL shells out to a teardrop configuration. The filaments and fans are field aligned currents in a dusty plasma.

 

[Reality Check]

EC predicts that 173,583 asteroids should be comets

EC universe: Rocky bodies that have an orbit with an eccentricity above a minimum value will be comets.
There may be other factors involved but since there is no actual EC model there is no list available.

There are 4 observed main-belt comets with a minimum eccentricity of 0.1644 (133P/Elst-Pizarro). So the EC minimim must be this (or lower!).

Real universe: There are rocky bodies that have an orbit with an eccentricity above a minimum value that are not comets.
In fact there are asteroids in orbits that are get close to cometary orbits, e.g. 2005 VX3 with an eccentricity of 0.9955142)

The JPL Small-Body Database Browser has a search engine. This shows that there are 173,583 cataloged asteroids with an eccentricity > 0.17.

The EC excuse (according to Sol88) is that low solar activity is the reason that these 173,583 cataloged asteroids are not comets. What Sol88 has not realized is that each asteroid is observed a number of times over a period of days to years. These 173,583 cataloged asteroids were not clse to the the Sun at the same instant of time. These asteroids were observed during a range of solar activity. That range included times that comets were visible.

So how many of these should be comets?

EC has no actual physical model and so never gives numbers so we do not expect help there.

Conclusion: EC currently predicts that 100% of the 173,583 asteroids should be comets.
We could be generous and assume that average solar activity is needed and so there are 86,791 asteroids that should be comets according to the EC idea. But that can wait until an EC proponent comes up with actual observations related to EC !


Good examples of the asteriods that should be comets according to the EC idea are many of the named asteroids:

• Juno (e=0.2553, observed over a span of 67,610 days).
• Pallas (e=0.2309, observed over a span of 64,291 days)
• Astraea (e=0.1917, observed over a span of 59,759 days)
• ...More than 46 other named asteroids observed 1000's of times over decades.
• Vera (e=0.1939, observed over a span of 45,191 days)

This analysis is in fact being generous to the EC idea. A stricter analysis would be to look at the orbital parameters of all comets (not just main-belt comets). This shows that the comet 158P/Kowal-LINEAR has an eccentricity of 0.0279 and a perihelion distance of 4.594 AU.

There are 459,893 asteroids with eccentricities greater than 0.0279.

 

[Sol88]

EC universe: Rocky bodies that have an orbit with an eccentricity above a minimum value will be comets.
There may be other factors involved but since there is no actual EC model there is no list available.

There are 4 observed main-belt comets with a minimum eccentricity of 0.1644 (133P/Elst-Pizarro). So the EC minimim must be this (or lower!).

Real universe: There are rocky bodies that have an orbit with an eccentricity above a minimum value that are not comets.
In fact there are asteroids in orbits that are get close to cometary orbits, e.g. 2005 VX3 with an eccentricity of 0.9955142)

The JPL Small-Body Database Browser has a search engine. This shows that there are 173,583 cataloged asteroids with an eccentricity > 0.17.

The EC excuse (according to Sol88) is that low solar activity is the reason that these 173,583 cataloged asteroids are not comets. What Sol88 has not realized is that each asteroid is observed a number of times over a period of days to years. These 173,583 cataloged asteroids were not clse to the the Sun at the same instant of time. These asteroids were observed during a range of solar activity. That range included times that comets were visible.

So how many of these should be comets?

EC has no actual physical model and so never gives numbers so we do not expect help there.

Conclusion: EC currently predicts that 100% of the 173,583 asteroids should be comets.
We could be generous and assume that average solar activity is needed and so there are 86,791 asteroids that should be comets according to the EC idea. But that can wait until an EC proponent comes up with actual observations related to EC !


Good examples of the asteriods that should be comets according to the EC idea are many of the named asteroids:

• Juno (e=0.2553, observed over a span of 67,610 days).
• Pallas (e=0.2309, observed over a span of 64,291 days)
• Astraea (e=0.1917, observed over a span of 59,759 days)
• ...More than 46 other named asteroids observed 1000's of times over decades.
• Vera (e=0.1939, observed over a span of 45,191 days)

This analysis is in fact being generous to the EC idea. A stricter analysis would be to look at the orbital parameters of all comets (not just main-belt comets). This shows that the comet 158P/Kowal-LINEAR has an eccentricity of 0.0279 and a perihelion distance of 4.594 AU.

There are 459,893 asteroids with eccentricities greater than 0.0279.

ETA RC

What is 2005 VX3's orbital period?