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The Electric Comet Theory /SAFIRE Part VI

The Plasma Environment of Comet 67P/Churyumov-Gerasimenko

From wake effects it can also be deduced that the bulk plasma flow is radial and supersonic. An ion velocity higher than the neutral velocity is in direct contradiction with the assumption that ions and neutrals are collisionally coupled
and thus in direct contradiction with the model suggested by Cravens (1987).

Vigren and
Eriksson (2017) showed that such a discrepancy can be explained by low collision rates due to low neutral gas densities and propose that an ambipolar electric field (see also Sect. 4.1) can accelerate ions to the observed velocities.

Fuselier et al. (2016) also pointed out that the unexpected H2O+ /H3O+ ratio can be explained by an ambipolar field inside the diamagnetic cavity. It should also be noted that the definition of the collisionopause as a sharp boundary that separates a region where neutrals and ions are coupled from a region where they are not coupled is inappropriate, since collisions are a process that occurs on length scales comparable with the diamagnetic cavity size (Vigren and Eriksson 2019).

As of now, it is unclear which process is responsible for deterring the magnetic field from diffusing into the diamagnetic cavity.

JD116, would you like to have a rethink on your position of a diamagnetic cavity caused by expanding gas?

Double layer....
The same ambipolar field that accelerates the ions retards the electrons and couples them more efficiently to the neutral gas via collisions

Whereas solar wind electrons are typically warm (around 10 eV),at large heliocentric distances (low outgassing) they are accelerated by an ambipolar electric field in the vicinity of the nucleus and reach energies of a few tens of eV responsible for ionisation and excitation of the cometary neutrals.
 
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Unfortunately, no model can adequately treat both large and small scales alike.
pity 'cos
Large-scale electric fields include the convective, ambipolar and polarization electric field. They affect both the ions and electrons, and are important for instabilities and wave
generation
.

Sounds like a problem with the mainstream model!
 
Sounds like a problem with the mainstream model!

Nope, not at all, but if you happen to have a few billion dollars/euros/pounds to build an super-super-super computer, then the problem would be solved.

I will set up a kickstarter for you.
 
mmmmmmmmmm doughnuts

Conclusions. The ambipolar and polarisation electric fields both have a significant influence on the motion of cometary ions. This demonstrates the importance of space charge effects in comet plasma physics.
https://www.researchgate.net/publication/336966567_Polarisation_of_a_small-scale_cometary_plasma_environment_Particle-in-cell_modelling_of_comet_67PChuryumov-Gerasimenko



Local process... did the team consider the nucleus to be at a different potential to the local space charge?

Where are all these cold electrons comming from...:D

Are we settled on the electric fields doing the works after that?

Paper pretty well confirms the importance of the plasma environment in comets.

Asteroid and moons too strangely enough.

Plasma,ay. :D

Maybe you could run the nOobs thru what “space charge effects” are? In relation to charged particles in a particular.
 
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Too scary, space charge effects?

Space charge effects have significant influence on the motion of cometary ions and electrons.

Plasma stuff. Electric currents, electric fields, instabilities inc DOUBLE LAYERS (Ambipolar electric fields).

Wow space charge stuff, very electric comet.

Large-scale electric fields include the convective, ambipolar and polarization electric field. They affect both the ions and electrons, and are important for instabilities and wave generation.

Comets therefore cover an extensive part of parameter space and present an excellent laboratory to study large scale structures as well as small scale interactions.
The Plasma Environment of Comet 67P/Churyumov-Gerasimenko

:thumbsup:
 
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We could just skip to my favorite:


5.2 Open Questions
1. What is the impact of electric field acceleration and dust charging on the plasma balance and vice versa?

2. What is the combined effect of the polarisation and ambipolar electric fields?

Is the dust charged, tusenfem?

What is the combined effect of the polarisation and ambipolar electric fields on the motion of the charged dust?

You up for it again?

For example, could there be strong nanodust releases at outbursts from the nucleus, or some high energy electron events causing so much charging of dust grains that electrostatic fragmentation near the nucleus becomes very strong, yielding lots of sub-micron grains and corresponding dust-plasma interactions effects? There may still be surprises awaiting us even in the existing datasets.

:deadhorse
 
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Direct measurement of decimetre-sized rocky material in the Oort cloud Published: 12 December 2022

This corresponds to an abundance of rocky meteoroids of ∼6+13−5% of all objects originating in the Oort cloud and impacting Earth to these masses. Our result gives support to migration-based dynamical models of the formation of the Solar System, which predict that significant rocky material is implanted in the Oort cloud, a result not explained by traditional Solar System formation models.

Planets doing handbrake turns around the solar system...awesome!

PR...

'Unexpected' space traveler defies theories about origin of solar system

Researchers from Western have shown that a fireball that originated at the edge of the solar system was likely made of rock, not ice, challenging long-held beliefs about how the solar system was formed.

:whistling

Dirty snowballs!
 
We could just skip to my favorite:




Is the dust charged, tusenfem?

What is the combined effect of the polarisation and ambipolar electric fields on the motion of the charged dust?

You up for it again?



:deadhorse

Still fogging a dead horse. Before the dust can get charged to any extent, and be affected by electric fields, it needs to get into the coma. And there is only one way that can happen. As observed.
 
Still bluing with jd116 on his misinterpretation of what the diamagnetic cavity is.

Mmmmmm....local process.

I know what the diamagnetic cavity is. You don't, and had never even heard of it until the Rosetta mission, despite us knowing about it from the mid-80s! What does the lack of a magnetic field in that cavity tell you about the impossible electric discharge woo you need on the surface? Where did your high priests deal with this in their fantasy pdf?

Need I remind you that a diamagnetic cavity was detected in the AMPTE experiments in 84/85? And all that experiment involved was gas.
 
Nope, and nobody is saying it isn't. Whether it is ion-neutral friction (most likely at Halley), or electron-neutral friction, is is still due to gas expanding from the comet.


What are you on about cobber?

Key Points

The ion velocity exceeded the neutral velocity, showing that the ions were not strongly collisionally coupled to the neutral gas

A population of warm electrons was present throughout the parts of the cavity reached by Rosetta, driving the spacecraft potential negative

A population of cold electrons was consistently observed inside the cavity and intermittently also in the surrounding region

If there is no electric field, or if the ions are strongly collisionally coupled to the neutrals, the ions can thus be expected to be cold and flowing with the neutral gas.

In the presence of a magnetic field of solar wind origin, the assumption of no electric field fails because of the existence of a convective electric field, which will cause the ions to gyrate, E × B drift, and eventually become dynamically part of the solar wind flow (which will be decelerated and deflected by mass loading; Coates, 2004; Szegö et al., 2000).
E. Odelstad
 
I know what the diamagnetic cavity is. You don't, ....


Gas pressure!

:dl:

It is and has always been the ELECTRIC FIELD...

This indicates that the ions were not collisionally coupled to the neutrals and implies that the ion-neutral drag force was not responsible for balancing the outside magnetic pressure at the cavity boundary. It also suggests the existence of an ambipolar electric field to accelerate the ions, at least inside the cavity.

This is consistent with the notion of Henri et al. (2017) that the formation and extent of the cavity is related to electron-neutral collisionality, if not directly by electron-neutral collisional drag at the cavity boundary then perhaps indirectly through its effect on the electron dynamics and electric fields (e.g., an ambipolar field) inside the cavity.
 
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Electric field acknowledged.:D

However, Ip and Axford [1987] and Cravens [1986, 1987] found this to be insufficient to explain the extent of the cavity observed at Halley and instead invoked the ion-neutral drag force inside the cavity to balance the outside magnetic pressure. This was supported by observations of near-equal ion and neutral velocities inside the cavity (∼1 km/s and ∼0.9 km/s, respectively), consistent with strong ion-neutral collisional coupling, and clear stagnation of the ion flow in the region just outside the cavity boundary...................Vigren and Eriksson [2017] used a 1D model to simulate the radial acceleration of water group ions interrupted by collisions (primarily charge transfer processes) with neutral water molecules, taking into account the energy-dependence of the cross-sections. They found that for an outgassing rate ∼2·1028 s−1, typical of 67P near perihelion, even a weak electric field of 0.03 mV/m, typical of what would be expected for an ambipolar field, is sufficient to partially decouple the ions from the neutrals, giving a bulk ion velocity of about 4 km/s at distances ∼200 km from the nucleus, typical of the Rosetta spacecraft around perihelion.
For an outgassing rate ∼2·1029 s−1, closer to that of Halley during the Giotto encounter (6.9·1029 s−1 [Krankowsky et al., 1986]), collisional coupling was found to prevail.

So, the cavity at Halley was due to ion-neutral friction. As I said. There is no evidence for an ambipolar field in the cavity at Halley, based on the ion velocities, which are coupled to the neutral velocities.

So;

Hence, Henri et al. suggested that the cavity formation and extent was the result of electron-neutral collisionality rather than the ion-neutral collisionality previously invoked. They also proposed a Rayleigh-Taylor type instability of the cavity boundary, driven by the electron-neutral drag force acting as an "effective gravity", instead of the Kelvin-Helmholtz type
suggested by Goetz et al. [2016a]............Finally, we have found that a population of cold (. 0.1 eV) electrons, first shown by Eriksson et al. [2017] to be intermittently present at Rosetta, is in fact observed consistently throughout the diamagnetic cavity. Already immediately outside the cavity, sweeps lacking a signature of cold electrons begin to turn up intermittently. This is consistent with the notion of Henri et al. [2017] that the formation and extent of the cavity is related to electron-neutral collisionality, if not directly by electron-neutral collisional drag at the cavity boundary, then perhaps indirectly through its effect on the electron dynamics and electric fields (e.g. an ambipolar field) inside the cavity.

The ions at 67P show velocities indicating an ambipolar field is present, as predicted by other authors. So, ion-neutral friction cannot be the cause of the cavity at 67P, unlike at Halley. Ergo, it appears to be due to electron-neutral interactions.

Clear enough?
 
So, the cavity at Halley was due to ion-neutral friction. As I said. There is no evidence for an ambipolar field in the cavity at Halley, based on the ion velocities, which are coupled to the neutral velocities.

So;



The ions at 67P show velocities indicating an ambipolar field is present, as predicted by other authors. So, ion-neutral friction cannot be the cause of the cavity at 67P, unlike at Halley. Ergo, it appears to be due to electron-neutral interactions.

Clear enough?

The ambipolar field is present. Electric field... full stop.

build yourself a bridge and get over it. You are wrong. :boggled:

Electron impact ionisation of rock, you say. Tell me more?

Happens at all rocky bodies including asteroids! Hell, even our moon.
 
The ambipolar field is present. Electric field... full stop.

build yourself a bridge and get over it. You are wrong. :boggled:

Electron impact ionisation of rock, you say. Tell me more?

Happens at all rocky bodies including asteroids! Hell, even our moon.

Posting more inane gibberish does not alter the fact that you are trivially wrong. And I said nothing about electron impact ionisation of rock. Learn to read.
And would you care to show where the diamagnetic cavities are at asteroids? And the Moon? You need gas. As the AMPTE experiments showed. Where is your rocky body in those experiments?
 
Interaction between the turbulent solar wind and a planetary magnetosphere: a 2D comet example

Though this 2-dimensional approach would benefit from a
future back up by additional 3-dimensional runs, the basic phe-
nomenon illustrated in this publication should remain, to some
extent, valid: upstream perpendicular magnetic field structures
will still pile-up and drape, self-consistently forming strong, un-
stable current sheets, at the location where the cometary plasma
is densest.
 
Right, so...um any turbulent plasma flows with nested magnetic fields in play at comets?

Quote:
One may think that such objects have nothing to do with space weather and large-scale streams or flows that impact the terrestrial magnetosphere causing a chain of effects potentially dangerous for human be-ings and the technosphere.

Meanwhile, recent observational studies show that CSs are intensively produced (i) in the turbulent region downstream of shocks, (ii) in corotating/stream interaction regions (CIRs/SIRs), and (ii) in magnetic cavities formed either by the HCS and an approaching high-speed stream/flow or by interact-ing SIRs and interplanetary coronal mass ejections (ICMEs).

Such CSs are associated with so-called magnetic islands that represent 2-D sections of 3-D plasmoids/blobs/flux ropes originating from magnetic re-connection considerably intensified in turbulent plasmas and magnetic cavities compressed from at least one side (Khabarova et al. 2015, 2016; Khabarova & Zank, 2017; Adhikari et al. 2019; Malandraki et al. 2019).

There’s ya diamagnetic cavity with bugger all neutrals involved. Especially, ICE.
 
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Right, so...um any turbulent plasma flows with nested magnetic fields in play at comets?



There’s ya diamagnetic cavity with bugger all neutrals involved. Especially, ICE.

Lol. Nothing to do with cometary diamagnetic cavities. Learn to read and get a grip. You haven't got a clue what you are talking about. Stick to the day job.
 
Right, so...um any turbulent plasma flows with nested magnetic fields in play at comets?



There’s ya diamagnetic cavity with bugger all neutrals involved. Especially, ICE.

Sigh. Do try to learn the difference between the words 'magnetic' and 'diamagnetic'.


This is the mag reading from one of the diamagnetic cavity crossings at 67P;


Discovery_of_diamagnetic_cavity (2).jpg


This is the magnetic field data from the magnetic islands;

ScreenHunter_46 Jan. 25 16.02.jpg

See a difference? The magnetic field readings are the ones with 'B' and 'nT'.
 
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There’s ya diamagnetic cavity with bugger all neutrals involved.

Well, we've already established that you don't know the difference between magnetic islands, which have a magnetic field within them, and a diamagnetic cavity that is essentially field free.

And you do realise that, regardless of diamagnetic cavities, the near-comae of comets are ~ 99.9999% neutral, yes?
 
See the Sun had a dummy spit at the green comet…

Zapped…

See if I can dig out the photo.
 
CME directed at the comet.

Comet, a rocky body trying to equalise charge (discharging) in the solar plasma, as travels deeper into the suns electric field.


If this rock has been out in the boonies, it should be of a higher negative potential compared to the suns more positively charge.

The ELECTRIC COMET.
 
CME directed at the comet.

Comet, a rocky body trying to equalise charge (discharging) in the solar plasma, as travels deeper into the suns electric field.


If this rock has been out in the boonies, it should be of a higher negative potential compared to the suns more positively charge.

The ELECTRIC COMET.

Nothing to do with either the Sun or a comet being charged. And nobody sane is claiming otherwise.
 
Not really saying it didn’t.

Now we know what reconnection is.

:cool:

We have known for a long time what reconnection is. We can even see it happen at an x-line on the Sun. As predicted. EUists have no explanation for MR.
 
THORNHILL
Wallace William (Wal)

Wallace William (Wal) Thornhill
2 May 1942 – 7 February 2023

Passed away peacefully in Canberra,
surrounded by family.

Much loved and devoted husband of 57 years of Faye. Loving father of Nikki, Tanya and Bronwyn and their partners Gal and Brian. Proud Pop of Hannah, Laura, Joel, Joshua, Jordan, Ela, Zohar, Sean and Tara. Proud Grand Pop of Ainsley.

Physicist - Cosmologist
Natural Philosopher
Independent Thinker

Wal was a world leading theorist of
Electric Universe cosmology; the chief
science advisor to The Thunderbolts Project; a science consultant for the Safire Project.

A celebration of Wal's life will be held at The Chapel, Gold Creek on Friday
17th February at 2pm.

Gone too soon - in our hearts forever
 
THORNHILL
Wallace William (Wal)

Wallace William (Wal) Thornhill
2 May 1942 – 7 February 2023

Passed away peacefully in Canberra,
surrounded by family.

Much loved and devoted husband of 57 years of Faye. Loving father of Nikki, Tanya and Bronwyn and their partners Gal and Brian. Proud Pop of Hannah, Laura, Joel, Joshua, Jordan, Ela, Zohar, Sean and Tara. Proud Grand Pop of Ainsley.

Physicist - Cosmologist
Natural Philosopher
Independent Thinker

Wal was a world leading theorist of
Electric Universe cosmology; the chief
science advisor to The Thunderbolts Project; a science consultant for the Safire Project.

A celebration of Wal's life will be held at The Chapel, Gold Creek on Friday
17th February at 2pm.

Gone too soon - in our hearts forever

Oh well, at least the electric comet 'model' won't die with him. It pre-deceased him!
 
THORNHILL
Wallace William (Wal)

Wallace William (Wal) Thornhill
2 May 1942 – 7 February 2023

Passed away peacefully in Canberra,
surrounded by family.

Much loved and devoted husband of 57 years of Faye. Loving father of Nikki, Tanya and Bronwyn and their partners Gal and Brian. Proud Pop of Hannah, Laura, Joel, Joshua, Jordan, Ela, Zohar, Sean and Tara. Proud Grand Pop of Ainsley.

Physicist - Cosmologist
Natural Philosopher
Independent Thinker

Wal was a world leading theorist of
Electric Universe cosmology; the chief
science advisor to The Thunderbolts Project; a science consultant for the Safire Project.

A celebration of Wal's life will be held at The Chapel, Gold Creek on Friday
17th February at 2pm.

Gone too soon - in our hearts forever

I’m sure he was a great guy and I sympathise with those who mourn his passing, but he was absolutely not, in any sense, a physicist or cosmologist, or a scientist of any kind.
 
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