Researchers have evidence that might explain the unexpected presence of energetic electrons in Mercury's magnetic tail

April 17, 2018, American Institute of Physics
Credit: NASA

Theoretical physicists used simulations to explain the unusual readings collected in 2009 by the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission. The origin of energetic electrons detected in Mercury's magnetic tail has puzzled scientists. This new study, appearing in Physics of Plasmas, provides a possible solution to how these energetic electrons form.

Magnetic material's flow inside a planet creates a global magnetic field. In Mercury, and in Earth, liquid metal currents in the planetary cores induce the ' magnetic fields. These fields vary in shape, size, angle and strength from planet to planet, but are all important for protecting planets from solar particles.

Solar wind blasts planets with radiation and causes magnetic substorms, which we sometimes see on Earth as the northern lights. Magnetic tails or magnetotails form when intense radiation pressure from solar winds "pushes" on the planet's magnetic fields. These tails form on the nighttime side of the planet, facing away from the sun. On Mercury, in the tail are bigger and more rapid than those observed on Earth.

Mercury's magnetic field is 100 times weaker than Earth's, so it surprised physicists that MESSENGER detected signs of energetic electrons in the planet's magnetic tail—the Hermean magnetotail. "We wanted to find out why the satellite found ," said Xiaowei Zhou, an author of the study.

A likely candidate responsible for the presence of these energetic particles is . Magnetic reconnection occurs when the arrangement of lines change, releasing kinetic and thermal energy. However, in the turbulent astrophysical environment, magnetic reconnection is poorly understood. In this study, Chinese and German physicists investigated magnetic reconnection within the context of turbulence in the Hermean magnetotail.

Magnetohydrodynamic simulations and test particle calculations showed that plasmoids—distinct magnetic structures that encompass plasma—are generated during magnetic reconnection. These plasmoids accelerate . The simulation results are supported by MESSENGER measurements of plasmoid species and plasmoid reconnection in the Hermean magnetotail.

The researchers also used a mean-turbulence model to describe the turbulence of subgrid-scale physical processes. Acceleration processes were scaled to parameters that mimic characteristic conditions reported from the Hermean magnetotail. The simulations showed that in these conditions, turbulent plasmoid reconnection could be responsible for electron acceleration. "We also showed that turbulence enhances reconnection by increasing the reconnection rate," Zhou said.

The team's model predicts the upper limits for turbulent plasmoid and the corresponding electron acceleration. The Bepi-Colombo mission, due to launch October 2018, will test these predictions. The Bepi-Colombo satellites, built to withstand the harsh, hot environment near the sun, will be inserted into Mercury's orbit in 2025 for one Earth year to transmit observations from the planet.

"Previous satellites could not test the high energies from electrons and one aim of this mission is to measure the energetic particles from the Hermean magnetotail with new detector technology," Zhou said. With this new technology, the researchers hope to gain a more detailed subscale view of the effects of turbulence.

Explore further: MAVEN mission finds Mars has a twisted tail

More information: "Electron acceleration by turbulent plasmoid reconnection," Physics of Plasmas (2018). DOI: 10.1063/1.5011013

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RealityCheck
2.1 / 5 (7) Apr 17, 2018
@cantdrive85 and @jonesdave.

To try and forestall more of your mutual insults and feuding 'noise', I will just point out that newer crop of researchers are coming round to more correct description/labeling of what is happening. As I have long been pointing out, its the PLASMA FLOWS/CURRENTS/PLASMOID contents etc that "reconnect"; causing the magnetic fields to RE-arrange accordingly...as more researchers are increasingly acknowledging:
Chinese and German physicists investigated magnetic reconnection within the context of turbulence in the Hermean magnetotail.
Magnetohydrodynamic simulations and test particle calculations showed that plasmoids—distinct magnetic structures that encompass plasma—are generated during magnetic reconnection. These plasmoids accelerate energetic electrons. The simulation results are supported by MESSENGER measurements of plasmoid species and plasmoid reconnection in the Hermean magnetotail.
OK guys,take it from there. Play nice now, ok? :)
jonesdave
5 / 5 (6) Apr 20, 2018
OK guys,take it from there. Play nice now, ok? :)


What's to discuss? The article claims it is due to MRx. Cantthink claims that cannot happen. Their results are based on MHD sims, and cantthink claims MHD is invalid. So, it is fully in line with mainstream science, and completely at odds with the lightning bolt cultists.
cantdrive85
1 / 5 (5) Apr 20, 2018
The article claims it is due to MRx. Cantthink claims that cannot happen. Their results are based on MHD sims, and cantthink claims MHD is invalid.

The mainstream scientists were "surprised" by the "unexpected" energetic electrons. They were surprised because their models failed.
Then they invoke more pseudoscience such as "plasmoid reconnection" to find an ad hoc explanation. And jonesdumb thinks this is a success. LOL!
cantdrive85
1 / 5 (5) Apr 20, 2018
If they are invoking plasmoids, then there will be double layers. This is an undeniable fact, as such their MHD and MRx models are utterly useless. The double layers are part of a circuit and the entire system must be described as a circuit system.
BTW, "magnetic reconnection is pseudoscience" Hannes Alfven
jonesdave
5 / 5 (5) Apr 20, 2018
magnetic reconnection is pseudoscience" Hannes Alfven


"No, it isn't." Carl-Gunne Falthammar. And he would know a lot more about it than Alfven ever did.
jonesdave
5 / 5 (4) Apr 20, 2018
The mainstream scientists were "surprised" by the "unexpected" energetic electrons. They were surprised because their models failed.


So show me within the scientific literature (or elsewhere) where non-mainstream scientists predicted this. If you can't, then you are just blowing smoke out of your arse, as usual.

cantdrive85
1 / 5 (4) Apr 20, 2018
Energetic electrons are a side effect of double layers, and double layers in plasmas are ubiquitous. Any non plasma ignoramus would not be surprised by their mere presence.
jonesdave
5 / 5 (6) Apr 20, 2018
Energetic electrons are a side effect of double layers, and double layers in plasmas are ubiquitous. Any non plasma ignoramus would not be surprised by their mere presence.


Which double layers? I've read the paper, and they are nowhere to be seen. I also read some of the referenced material regarding the MESSENGER observations - again, no observation of double layers. Not seen in the simulations, not seen in-situ. Not required to explain anything. Ergo, the principle of parsimony says we can discount them.
Da Schneib
5 / 5 (4) Apr 20, 2018
Next up, @cantthink69 declares that @jones "denies the existence of plasma."

In 3,... 2,... 1,...
cantdrive85
1 / 5 (3) Apr 20, 2018
MESSENGER did not have the resolution to detect the double layers. Hell, it wasn't until MMS and Van Allen probes where multiple spacecraft were used was this phenomena definitively detected in near-Earth space. It takes a very specific resolution to be able to detect them.
However, anyone who has real laboratory experience with plasmoids will tell you that double layers absolutely are part and parcel to plasmoids. It is why the plasmoid has "structure", it is an undeniable fact.
And you are correct, their MHD models don't predict/resolve double layers, Alfvén said this long ago and is why MHD models are invalid.
"As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by menas of double layers."
Alfvén
"We may conclude that anyone who uses the merging concepts states bv implication that no double layers exist."
Also Alfvén
https://inis.iaea...18060222
jonesdave
5 / 5 (5) Apr 20, 2018
"We may conclude that anyone who uses the merging concepts states bv implication that no double layers exist."


So, that would be Falthammar and pretty much every plasma physicist alive, then. And yet I know a PP who is perfectly fine with reconnection, yet did his PhD on DLs at Alfven's lab in Sweden. Have a look at the Wikipedia entry on DLs - I think he wrote a fair chunk of it.
The problem with EU is that they have no plasma physicists amongst them, and therefore continually have to call on misinterpretations of stuff Alfven said decades ago. They don't have anyone capable of understanding the subject themselves, and the subject has moved on in the 25 years plus since Alfven had anything to do with it.
cantdrive85
1 / 5 (4) Apr 20, 2018
So, that would be Falthammar and pretty much every plasma physicist alive, then.

Yep, and why the plasma ignoramuses are always surprised, shocked, perplexed, and continuously find that which is unexpected, like the story above points out.
Have a look at the Wikipedia entry on DLs - I think he wrote a fair chunk of it.

I can tell it was written by a plasma ignoramus, he keeps referring to laboratory power supplies yet seems to fail to comprehend the power supply in natural plasmas. Typical of a plasma ignoramus unable to grasp there is electric energy in plasmas.
Da Schneib
5 / 5 (3) Apr 20, 2018
Plus plasma physics is now all full of scary integrals and PDEs. And stuff.

For every phenomenon there is a hypothesis that is simple, easy, obvious, and completely, idiotically wrong.
jonesdave
5 / 5 (4) Apr 20, 2018
Yep, and why the plasma ignoramuses are always surprised, shocked, perplexed, and continuously find that which is unexpected, like the story above points out.


Nope. They get far more right than wrong. And, let's be honest, you lot never get anything right, as you don't have anyone that can even do plasma physics. You never produce anything, other than whining on places like this. You are incapable of doing the science, but see fit to criticise it. Rank hypocrisy, I call that. Now, what is a collisionless plasma again? Pot and kettle, eh?
jonesdave
5 / 5 (4) Apr 20, 2018
Typical of a plasma ignoramus unable to grasp there is electric energy in plasmas.


Why don't you tell him woo boy? Just sign up at ISF or Cosmoquest, and away you go. However, we all know you have neither the cojones nor the knowledge to be able to debate an actual plasma physicist. You just want to do your Dunning-Kruger, Walter Mitty stuff on here, for whatever weird psychological reasons.
cantdrive85
1 / 5 (4) Apr 20, 2018
Just sign up at ISF or Cosmoquest, and away you go

He is welcome here too. You're such good friends you should invite him on over.
cantdrive85
1 / 5 (5) Apr 20, 2018
And, let's be honest, you lot never get anything right, as you don't have anyone that can even do plasma physics.

Real plasma physics;
"SAFIRE generates the same energy densities as the sun's photosphere and nuclear bombs …

... in a laboratory on Earth"
http://safireproj...dex.html
jonesdave
5 / 5 (3) Apr 21, 2018
Just sign up at ISF or Cosmoquest, and away you go

He is welcome here too. You're such good friends you should invite him on over.


Pointless. You need a lesson in plasma physics that would require equations and a whole lot more than 1000 characters. We all know you're too chicken to take your naive misunderstandings to an actual physics forum. Dodge all you like, but you belong to a cult that wouldn't recognise plasma physics if it fell over it, and has no interest in being shown up by actually having to debate it with experts in the field. Of which you have zero.
jonesdave
5 / 5 (4) Apr 21, 2018
And, let's be honest, you lot never get anything right, as you don't have anyone that can even do plasma physics.

Real plasma physics;
"SAFIRE generates the same energy densities as the sun's photosphere and nuclear bombs …

... in a laboratory on Earth"
http://safireproj...dex.html


Lol. SAFIRE, based on the premise that the Sun is a giant lightbulb! According to the abysmally ignorant Don Scott. What is supplying this metal sphere with power? Is the Sun a metal sphere? Where is the solar system equivalent of the mains supply that is powering the metal ball? Is it producing a solar wind of equal parts - & +, all travelling outward at the same speed? Is it producing the observed neutrino count? Finally; what is the point of it? Will the paper (assuming there ever is one) be entitled; "What happens when you stick a squillion volts through a metallic sphere."?
cantdrive85
1 / 5 (5) Apr 21, 2018
SAFIRE, based on the premise that the Sun is a giant lightbulb!

That's what the spectroscopy would suggest.
What is supplying this metal sphere with power?

Electric currents, you know, plasma.
Where is the solar system equivalent of the mains supply that is powering the metal ball?

There is a lot of iron visible, but ultimately it need only be plasma. Peratt has indicated that due to the electrical properties of metal it is basically a plasma.
And the currents feeding the solar system were found already;
http://electric-c...2012.pdf
http://electric-c...2013.pdf
https://agupubs.o...GL048763
From that paper;
"The IBEX maps reveal, superposed on a global ENA background, an enigmatic "ribbon" of enhanced ENA emission, a feature unpredicted by theory and numerical simulations and requiring a new paradigm for the heliosphere/LISM interaction."
Failed model!
cantdrive85
1 / 5 (5) Apr 21, 2018
The ultimate irony is Birkeland used a very similar approach to discover how Earth's auroras are created, obviously lost on jonesdumb.
jonesdave
5 / 5 (4) Apr 21, 2018
That's what the spectroscopy would suggest.


Wrong. It is a thermal, blackbody spectrum. Idiot.

And the currents feeding the solar system were found already;


Lol. no they weren't. Idiot. ENA = energetic NEUTRAL atom emission. And the first two links are from a crank website, where they can't seem to understand that the electrons (nowhere near enough to power a star) are only seen at the heliopause. If they were making their way in all the way to the Sun, then why are we not detecting them at 1 AU? With far better equipment than that carried by a 1970s probe? And why wasn't Voyager detecting them at,lesser distances? Because they aren't there. It is unscientific nonsense, which nobody takes seriously.
jonesdave
5 / 5 (4) Apr 21, 2018
There is a lot of iron visible


No, there isn't. Fe makes up a tiny percentage of the elements in the Sun.

http://curious.as...beginner
cantdrive85
1 / 5 (3) Apr 22, 2018
We see the iron where we'd expect it if the surface (not photosphere) has iron. We see FeH in sunspots, where we can see down to the cooler solar surface.
It is a thermal, blackbody spectrum. Idiot.

"The surfaces of stars can be explained as lightning discharges which are observed in the atmosphere of the Earth" C.E.R. Bruce

ENA = energetic NEUTRAL atom emission

Nobody could ever confuse you for a thinker, could they? They became NEUTRAL due to charge exchange, you know electric discharge. And their location and behavior completely falsified the standard theory model of the heliosphere, but who cares about falsification when ad hoc patches are so popular.

cantdrive85
1 / 5 (3) Apr 22, 2018
where they can't seem to understand that the electrons (nowhere near enough to power a star) are only seen at the heliopause. If they were making their way in all the way to the Sun, then why are we not detecting them at 1 AU?

There are actually 20,000 times more electrons than needed to power an Electric Sun, as measured by Voyager given the size of the heliosphere (5x10^27m2).
And when the motion of the solar wind is like this;
https://phys.org/...lar.html
There is no way to determine what all of the electrons are doing. Only a small ratio of the electrons will be drifting toward the Sun.

SkyLight
2.3 / 5 (3) May 03, 2018
Only a small ratio of the electrons will be drifting toward the Sun.
Drifting... and then they're supposed to be energetic enough, when they land there, to give rise to the nuclear reactions your religion says occur at the Sun's surface. Which is made of iron...

What utter, unscientific, incomprehensibly thick-headed nonsense.

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