Electric comets - discharges within the coma

[upriver]

I found this. Stating the obvious; not only is there a density (of the plasma) component but there has to be an energy input (photon) component.

Brant


"from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
Stark Effect "
"The term “Stark effect” is applied not only to the splitting of spectral lines in electric fields but also to the shift and splitting of energy levels in such fields.

<snip>

The linear Stark effect is characteristic of hydrogen in electric fields that are not too strong. For example, in fields of ~10^4 volts per cm (V/cm), the effect amounts to a few thousandths of an electron volt. An energy level of a hydrogen atom with a given principal quantum number n is split symmetrically into 2n – 1 equidistant sublevéis (Figure 1 corresponds to n = 3, 2n – 1 = 5). The components of a spectral line that is split in a field E are polarized. If the direction of E is perpendicular to an observer, some of the components—called the π components—are polarized parallel to the field, while the remaining components— known as the σ components—are polarized perpendicular to the field. When observed in the direction longitudinal to the field, the π components do not appear and the cr components are replaced by unpolarized components. The intensities of the various components differ. The splitting of the Hα spectral line of hydrogen (the first line of the Balmer series) as a result of the Stark effect in shown in Figure 3.

The linear Stark effect is also observed in hydrogen-like atoms (He +, Li2+, Be3+, . . . ) and for highly excited states of other atoms; in a number of cases, the effect results in the appearance of forbidden lines. The quadratic Stark effect, which exhibits an asymmetric splitting pattern, is typical of many-electron atoms. The magnitude of the quadratic effect is small. For example, in fields of ~10^5 V/cm, the splitting amounts to a few ten-thousandths of an electron volt. The linear Stark effect is characteristic of molecules that are sufficiently symmetric and have a constant dipole moment. In other cases, the quadratic Stark effect is usually observed.

An important case of the Stark effect is the splitting of the electronic energy levels of an ion in a crystal lattice under the influence of the crystalline field Ecr, which is generated by surrounding ions. Such splitting may be as high as a few hundredths of an electron volt, is taken into account in crystal spectroscopy, and is essential for the operation of quantum mechanical amplifiers.

The Stark effect is also observed in variable electric fields. The change in the position of the Stark sublevéis in a variable field Emay be used to vary the frequency of a quantum transition in quantum-mechanical devices. An example is Stark modulation (seeMICROWAVE SPECTROSCOPY).

In particular, the influence of a rapidly varying electric field on the energy levels of atoms or ions determines the Stark broadening.....


REFERENCES
El’iashevich, M. A. Atomnaia i molekuliarnaia spektroskopiia. Moscow, 1962.
Frish, S. E. Opticheskiespektry atomov. Moscow-Leningrad, 1963.
Townes, C., and A. Shawlow. Radiospektroskopiia. Moscow, 1959. (Translated from English.)"

http://encyclopedia2.thefreedictionary.com/Stark+Effect

[David Talbott]

Upriver and others, it's hard for me to imagine that the Stark effect is not present in activity close to comet nuclei. I'll check with Wal on this, but perhaps this would qualify as a prediction of the electric model.

To what extent we should expect such energy levels from electric fields elsewhere in the coma is a good question and far from clear in my mind.

[Nereid]

Quick note: I have found no mention of any [OI] 112.8 nm lines in any published FUSE observations (nor HUT, but I haven't looked at those very hard). There certainly are lines at 112.8 nm - e.g. P V, one member of a doublet, and Si IV, ditto; see Walborn et al. (2002) for example - but nothing on [OI] 112.8 nm.

Further, Feldman et al. (1991) - using HUT - report no detection of any 112.8 nm line in Comet Levy in 1990, which is interesting, or odd. Why? Because the two comets seem similar, and HUT should have detected a 112.8 nm line as prominent as that reported by Green et al.

Perhaps [OI] 112.8 nm fails the 'independently verifiable' test?

[David Talbott]

Nereid this is helpful info, though I keep wondering if there's a clear message in the data as a whole. I certainly believe Wal's inclusion of "forbidden lines" [OI] apparent in Austin's coma was a valuable pointer, but more a pointer to a line of investigation that has never been adequately carried out. One thing I'm hoping we can pull together in the next few months is a systematic exposition of the questions that must be asked in order to validate or falsify the electric comet model. Within our circle a lot of material has been released, but it needs to be summarized down to the acid tests.

My hope would be that the tests can be agreed upon by folks communicating across the present breach. One difficulty here is that a conventional consensus as to what a comet is no longer exists; and a second difficulty is that the Electric model is not complete in its explanation of the distinction between comets and asteroids (despite the fact that this distinction could be one of the acid tests of the electric model).

[Lloyd]

Dave T said: the Electric model is not complete in its explanation of the distinction between comets and asteroids

* Is a large part of the EU explanation that asteroids are in electrical [charge] equilibrium with their environment, while comets are not, and the reason being usually that comets, being on elliptical orbits, encounter a changing charge environment, while asteroids on less eccentric orbits do not?

[Nereid]

Nereid this is helpful info, though I keep wondering if there's a clear message in the data as a whole. I certainly believe Wal's inclusion of "forbidden lines" [OI] apparent in Austin's coma was a valuable pointer, but more a pointer to a line of investigation that has never been adequately carried out.

David, as far as I know - which is not much, I hasten to say - spectroscopy can be helpful in constraining models of the physical states of comet comas (and tails). It can, for example, provide evidence of the existence of various species of atoms, molecules, ions, radicals, etc, and their relative abundance. Also their temperatures and densities. Together with analyses of continuum emission, the density and size distribution of the dust may be able to be estimated too.

From the EU perspective, the good news is, I guess, that there's a lot of good, quantitative data already published in the literature, so once EU models have been developed sufficiently, they may be able to be tested quite quickly.

[mharratsc]

Ms. Nereid said:

From the EU perspective, the good news is, I guess, that there's a lot of good, quantitative data already published in the literature, so once EU models have been developed sufficiently, they may be able to be tested quite quickly.

Hopefully the forthcoming analysis vehicles in future experiments will carry more electrical diagnostics equipment to do just that, and that the results will provide some conclusive proof one way or another.

Otherwise- if it's simply a matter of applying an electrical interpretation on the already-existent data that has been returned from past missions... I do not carry any hopes that any publishing bodies will allow plasma paradigm research through peer-review moreso now than in the past (other than to continue to publish within the IEEE body.) :\

[Siggy_G]

* Is a large part of the EU explanation that asteroids are in electrical [charge] equilibrium with their environment, while comets are not, and the reason being usually that comets, being on elliptical orbits, encounter a changing charge environment, while asteroids on less eccentric orbits do not?

The first part of the explanation is plausible, but the mechanism needs clarification/elaboration. Except from the more extreme eccentric orbits by some comets, there exists both asteroids and comets of the same elliptical orbit, displaying different effects (tail vs no tail). People going against the electric comet hypothesis like to mention this one. So I don't know if it boils down to chemical / surface related processes over time. It occurs somewhat logical to me that the cometary material/surface may become electrically neutral at some point, but I need to research this or see anyone's response on the subject.

The other part that needs clarification is the measured/calculated density of asteroids versus comets. Asteroids are heavier/denser based on orbital calculations (velocity). Whether (dis)charge mechanisms affect the oribital velocity, and how, needs elaboration. I wondered whether drag effect ("aerodynamics") from the interplanetary medium could give a counter acceleration, but while the effect surely is there, calculations showed it to be way too tiny to have any significant impact on a massive comet. (For solar sails and low density objects on the other hand...).

[mharratsc]

Siggy_G said:

Except from the more extreme eccentric orbits by some comets, there exists both asteroids and comets of the same elliptical orbit, displaying different effects (tail vs no tail).

There aren't any bodies labeled 'asteroid' that have an elliptical orbit approaching anything like a comet, are there?

I know I've read of some of the asteroids that have more exotic orbits that will actually develop a comet-like coma (which is presumed in the Electric Comet model to occur because the elliptical orbit moves them through differing regions of charge)... but I haven't read of any of them moving out of the asteroid belt itself.

Is this correct?

[Siggy_G]

mharratsc, you're right, and I think I may have rushed my argument, and it was based on a list of refutations I read at the JREF a while back.
http://forums.randi.org/showpost.php?p=5061286&postcount=395

I realize it's a strawman: "because there are 6-7 mainbelt comets, they represent ALL comets, and therefore the hundreds of thousands asteroids with orbits of same/more eccentricity should also display cometary effects."

Now that is a blunt argument, because mainbelt comets are humbly thought by many astrophysicists to be "a little odd" in their behaviour, and the 6-7 mainbelt comets surely don't represent the thousands of reported comets, and trillions of estimated comets thought to exist within the solar system, of completelly different orbits.

[nick c]

Siggy G,

mharratsc, you're right, and I think I may have rushed my argument, and it was based on a list of refutations I read at the JREF a while back.
http://forums.randi.org/showpost.php?p= ... tcount=395

I realize it's a strawman: "because there are 6-7 mainbelt comets, they represent ALL comets, and therefore the hundreds of thousands asteroids with orbits of same/more eccentricity should also display cometary effects."

Now that is a blunt argument, because mainbelt comets are humbly thought by many astrophysicists to be "a little odd" in their behaviour, and the 6-7 mainbelt comets surely don't represent the thousands of reported comets, and trillions of estimated comets thought to exist within the solar system, of completelly different orbits.

Comet Holmes 17P, which flared up in the late 1800's and then again in 2007, qualifies as one example of this type of object. It's orbit is entirely between the orbits of Jupiter and Mars, that is in the asteroid belt.

So what might have happened to Comet Holmes? It is not a typical comet. The eccentricity of its orbit is minimal. It is always outside the orbit of Mars and inside the orbit of Jupiter. In fact, it is virtually as close to being an asteroid as it is to being a comet. And astronomers are slowly realizing that the distinctions between asteroids and comets are not as clear as they had once believed. Occasionally, asteroids sport cometary tails, like the asteroid Chiron, which was seen to develop a tail while orbiting between Saturn and Uranus around 1988 and 1989. It is now officially classified as both an asteroid and a comet. Since the electrical stresses on Holmes would be minimal, much like those on asteroids with modestly elliptical orbits, it is not unreasonable to assume that its plasma sheath remains largely undisturbed -- unless it penetrates into or is penetrated by another sheath with sufficient differential across its double layer to cause an explosive breakdown.

It's interesting to note that the diagram of Holmes' orbit shows that it crossed the ecliptic (the plane of the planets movement around the Sun) quite close to the time of its closest approach to Mars. So it is certainly conceivable that Mars' own plasma sheath, by penetrating that of Holmes, provoked the fateful breakdown. Though this would not qualify as a coherent hypothesis today, it is the kind of issue raised by the electric model that is systematically ignored by mainstream astronomers.

http://www.rense.com/general79/cmet.htm

And a similar but slightly different EU explanation by Thornhill, as related in a Thunderblog by Scott Wall:

In a private email, Thornhill suggested that:

"Outbursts from comets at great distances from the Sun seem to be correlated with a sudden change in the solar 'wind' plasma environment due to a solar storm. The point about sudden comet outbursts is that we are dealing with a sudden, discontinuous process of plasma discharge - a switch from dark current mode to normal glow mode. It is a complex surface phenomenon that cannot be predicted. The best we can do is to say that the passage of a sudden change in the solar wind is the most likely time to see a flareup."

The sun had been electrically active in the days before the "explosion". Upon investigation of data from the ACE satellite, see this movie or this graph, Michael Mozina noticed that there was a large spike in the density of the solar wind on October 22 at 19:45, two days before the infamous flareup. This spike likely switched the comet into normal glow mode and allowed it to grow. Once in normal glow mode, the plasma coma does not require a sustained voltage to maintain that mode.

http://www.thunderbolts.info/thunderblo ... _swall.htm

Nick

[StefanR]

The other part that needs clarification is the measured/calculated density of asteroids versus comets. Asteroids are heavier/denser based on orbital calculations (velocity). Whether (dis)charge mechanisms affect the oribital velocity, and how, needs elaboration. I wondered whether drag effect ("aerodynamics") from the interplanetary medium could give a counter acceleration, but while the effect surely is there, calculations showed it to be way too tiny to have any significant impact on a massive comet. (For solar sails and low density objects on the other hand...).

Are you hinting at such effects as these? :

Posted: Mon Nov 26, 2007 7:30 pm Post subject: non-gravitational forces/mainstream Reply with quote
Quote:
non-gravitational forces : Forces that are not of gravitational origin which act on asteroids and comets and that can sometimes significantly alter their orbits. Examples include reaction forces due to outgassing of volatile materials and the Yarkovsky and Poynting–Robertson forces.

Poynting–Robertson effect: A deacceleration and spiraling inward of small dust particles orbiting the Sun due to their interaction with solar radiation.

Yarkovsky effect : Acceleration due to recoil force caused by the thermal reradiation from an irregular object. This can cause substantial changes to asteroidal orbits and also affect their rotational states.

http://www.cambridge.org/us/catalogue/c%20...%20645&ss=fro

http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?p=323#p323

Comet Holmes 17P, which flared up in the late 1800's and then again in 2007, qualifies as one example of this type of object. It's orbit is entirely between the orbits of Jupiter and Mars, that is in the asteroid belt.

There were some subtleties to the orbit of Holmes:

Close approaches to planets: During the 20th century, this comet made two close approaches to Jupiter. There are also two close approaches to Jupiter during the 21st century. (From the orbital work of Kazuo Kinoshita and G. W. Kronk)

0.54 AU from Jupiter on 1908 December 9
increased perihelion distance from 2.12 AU to 2.34 AU
increased orbital period from 6.86 to 7.33 years
1.03 AU from Jupiter during 1968 April
decreased perihelion distance from 2.35 AU to 2.16 AU
decreased orbital period from 7.35 to 7.05 years
1.50 AU from Jupiter during 2004 January
decreased perihelion distance from 2.17 AU to 2.05 AU
decreased orbital period from 7.07 to 6.88 years
0.85 AU from Jupiter on 2051 April 8
increased perihelion distance from 2.06 AU to 2.21 AU
increased orbital period from 6.89 to 7.21 years

http://cometography.com/pcomets/017p.html

http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?p=323#p323

Some more info and links about comets and asteroids are in the Holmes-thread (dust, space-charging etc etc).

[flyingcloud]

The comet is Tempel 1, which NASA's Deep Impact probe visited in 2005. Now another NASA spacecraft, Stardust-NExT, is closing in for a second look on Valentine's Day, Feb. 14, 2011.

The layering is an interesting twist that should not exist with respect to "our" current understanding of these "dirty snowballs"

Stardust-NExT will reveal how the plateau has changed (Is it flowing?), helping the team determine its origin. Whatever their origin, the plateau and layering show that comets have a much more complicated geologic history than previously thought.

It's a history NASA has had a hand in. During its 2005 visit, Deep Impact dropped an 820-pound projectile into the comet's core. In a development that surprised mission scientists, the impact excavated so much material that the underlying crater was hidden from view. Deep Impact's cameras were unable to see through the enormous cloud of dust the impactor had stirred up. Stardust NExT could provide a long anticipated look at the impact site.

http://science.nasa.gov/science-news/sc ... rdustnext/

powdery flows or electrical discharges

[flyingcloud]

NASA Releases Images of Human-Made Crater on Comet

http://www.sciencedaily.com/releases/20 ... 205951.htm

NASA's Stardust spacecraft returned new images of a comet showing a scar resulting from the 2005 Deep Impact mission. The images also showed the comet has a fragile and weak nucleus.

"We see a crater with a small mound in the center, and it appears that some of the ejecta went up and came right back down," said Pete Schultz of Brown University, Providence, R.I. "This tells us this cometary nucleus is fragile and weak based on how subdued the crater is we see today."

http://www.nasa.gov/mission_pages/stard ... 0214d.html

[FS3]

I wonder what "astrognome" Pete Schultz is talking about when he seems to see a "hole" and without taking a deep breath he states that "...the ejecta went up and came right back down..." - in the same "crater" - so "filling up that 'ole" - why we can't see a 'ole at all...

Either...

- the "snowy dirtball" (LOL) is made up of such a dense material that the impact of "Deep(LOL) Impact" wasn't that "deep" at all...

- or the probe that was meant to cause that "impact" on Tempel 1 was destroyed before he actually could hit home by exactly that flash of light that we all saw on the pictures from 2005.

FS3