Pluto has some characteristics less like that of a comet and more like much larger planets, according to an analysis of Pluto's unique interaction with the solar wind, scientists say.
Using data from an instrument aboard the New Horizons spacecraft gathered on its Pluto flyby in July 2015, scientists have observed the material coming off of Pluto and seen how it interacts with the solar wind, and found it completely new – and unexpected.
"This is a type of interaction we've never seen before anywhere in our solar system," said David J. McComas, lead author of the new study published today in the Journal of Geophysical Research – Space Physics, a publication of the American Geophysical Union.
McComas, professor in Princeton University's Department of Astrophysical Sciences and vice president for the Princeton Plasma Physics Laboratory, leads the Solar Wind Around Pluto (SWAP) instrument aboard New Horizons; he also led development of SWAP when he was at the Southwest Research Institute (SwRI) in Texas. The research was funded as a part of the New Horizons project by NASA.
Space physicists say that they now have a treasure trove of information about how Pluto's atmosphere interacts with the solar wind. Solar wind is the plasma, or charged particles, that spews off from the sun into the solar system at a supersonic 400 kilometers per second (1 million miles per hour), bathing planets, asteroids, comets and interplanetary space in a soup of mostly electrons and protons.
"The results are astonishing. We were fascinated and surprised" by the findings, McComas said.
Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that's part gas- and part battery-powered, Pluto is a hybrid, the researchers say.
"This is an intermediate interaction, a completely new type. It's not comet-like, and it's not planet-like. It's in-between," McComas said. "We've now visited all nine of the classical planets and examined all their solar wind interactions, and we've never seen anything like this."
"These results speak to the power of exploration. Once again we've gone to a new kind of place and found ourselves discovering entirely new kinds of expressions in nature," said Alan Stern, New Horizons principal investigator at the Southwest Research Institute. "Many people were surprised by Pluto's complex geology and atmosphere. This paper shows there's even more that's surprising there, including its atmosphere-solar wind interaction."
Pluto continues to confound. Since it's so far from the sun – an average of about 5.9 billion kilometers (3.7 billion miles) – and because it's so small, scientists thought Pluto's gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, "Pluto's gravity clearly is enough to keep material sufficiently confined," McComas said.
Further, the scientists found that very little of Pluto's atmosphere is comprised of neutral particles converted to electrically charged ions and swept out into space.
"This is backwards for many other planets, where the neutral particles stay relatively close to the planet," said Michael Liemohn, a University of Michigan astrophysicist and Editor-in-Chief of JGR-Space Physics, who was not involved with the research but who helped edit the paper. "An ion particle becomes influenced by the electric and magnetic forces present in the solar system, which can be a very efficient acceleration processes. But at Pluto, McComas et al found that only a wisp of atmosphere leaves the planet as ions."
The researchers were able to separate the heavy ions of methane, the main gas escaping from Pluto's atmosphere, from the light ions of hydrogen that come from the sun using the SWAP instrument.
Among their Pluto findings:
- Like Earth, Pluto has a long ion tail, that extends downwind at least a distance of about 100 Pluto radii (119,000 kilometers (73,800 miles), almost three times the circumference of Earth), loaded with heavy ions from the atmosphere and with "considerable structure;"
- Pluto's obstruction of the solar wind upwind of the planet is smaller than had been thought. The solar wind isn't blocked until about the distance of a couple planetary radii (2,968 kilometers (1,844 miles), about the distance between Chicago and Los Angeles);
- Pluto has a very thin "Plutopause" – or boundary of Pluto's tail of heavy ions and the sheath of the shocked solar wind that presents an obstacle to its flow.
The scientists write: "Pluto interaction with the solar wind appears to be a hybrid with the bow shock generated by mass-loading like at a comet, but the obstacle to the solar wind flow – the Plutopause – sustained by atmospheric thermal pressure as at Venus and Mars."
Heather Elliott, astrophysicist at Southwest Research Institute and co-author on the paper, said that the study provides interesting comparisons. "Comparing the solar wind-Pluto interaction to the solar wind-interaction for other planets and bodies is interesting because the physical conditions are different for each, and the dominant physical processes depend on those conditions," Elliott said.
What is significant, McComas said, is the range of diversity that bodies in the solar system have with the solar wind. Further, the findings offer clues to the magnetized plasmas that one might find around other stars. "The range of interaction with the solar wind is quite diverse, and this gives some comparison to help us better understand the connections in and beyond our solar system," McComas said.
The scientists conclude: "The SWAP data will … be reanalyzed … for many years to come as the community collectively grapples with Pluto's unique solar wind interaction – one that is unlike that at any other body in the solar system."
New Horizons is the first mission in NASA's New Frontiers program, managed by the agency's Marshall Space Flight Center in Huntsville, Ala. The Johns Hopkins University Applied Physics Laboratory designed, built, and operates the New Horizons spacecraft and manages the mission under Principal Investigator Dr. Alan Stern's direction for NASA's Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning. The NASA Heliophysics program also supported the analysis of these observations.
Explore further:
Multitasking New Horizons observed solar wind changes on journey to Pluto
More information:
"Pluto's Interaction with the Solar Wind," D. J. McComas et al. , 2016, Journal of Geophysical Research - Space Physics, onlinelibrary.wiley.com/doi/10 … 016JA022599/abstract
cantdrive85
Maggnus
wduckss
Science rests on empty stories and fairy tales and it is not surprising that we have surprise, surprise ...
Phys1
jim_xanara
chileastro
Re: the trolls PO have doubled down on their promoting trolling. Last week we saw them delete an account for the generic statement that someone would love the chance to dance on the trolls' grave, yet trolls get seldom get accounts deleted for saying racist, personally threatening, slanderous statements, and just pure misinformation. Can anyone remember one having an account deleted for just one deleted post? It certainly wasn't up to the level of what the trolls do every day with impunity from the mods, so one can only conclude that they're running a little troll farm. I say we take serious discussion to the forum, which is moderated, and teach them which side their bread is buttered on by posting no comments on the articles. Let it be total troll spew and pretty clear what an embarrassment it all is.
FineStructureConstant
D'you see: the scientists behind this endeavour were HOPING to find something new and unexpected, and they did. If they hadn't wanted their precious "mainstream theories" to be called into question, they wouldn't have gone to all that trouble. Exploration, discovery, surprise: that's the name of science. You bozos are firmly excluded from science/space exploration because mythology has no place there.
Captain Stumpy
yep. for a death threat
although i think the account you're referring to likely got deleted for stating PO was pandering to the trolls... perhaps you contact the site and complain more about the trolls, liars, idiots and request moderation?
I've submitted a plan that would be minimal set-up cost (just adjusting some profiles for temp bans) and free moderation from the existing profiles, with a list of the best candidates known to be degree holing professionals (- not like gkam)
push for it
.
.
@FSC
funnier still, the lead author and contact VP's the Princeton Plasma Physics Lab
http://www.pppl.gov/news/2016/02/mccomas-named-vice-president-princeton-plasma-physics-laboratory" title="http://http://www.pppl.gov/news/2016/02/mccomas-named-vice-president-princeton-plasma-physics-laboratory" rel="nofollow" target="_blank">http://www.pppl.g...boratory
IOW- that study is chock full of folk who specialise in nothing but plasma physics
LOL
http://www.pppl.gov/
gkam
------------------------------------------
Let's compare university degrees, shall we? What university degree do you "hole"?
How about actual experience?
You first. You saw mine already, most of it. There is still a surprise or two for you to find, but that is most of it.
Give up your need to "get even" with those of us who proved you to be just a nasty guy with sensitive feelings, so we can discuss the science.
Captain Stumpy
your arguments tend to be predominantly anecdotal and from authority
when you claim to have a degree, therefore you *must* be correct despite the evidence proving you're wrong or lying then it stops being about science and becomes about a pathological need for attention (AKA- Trolling) and disruption of content with narcissistic promotion of self (sociopathic/psychopathic)
thus you demonstrate Dunning-Kruger, not science
See links below for evidence
http://phys.org/n...sed.html
http://phys.org/n...ess.html
http://phys.org/n...age.html
just to link a FEW
so my degree's are not relevant because i'm not making the argument from authority
reported for spamming/baiting/trolling per our agreement
gkam
Without a degree or experience in these fields, your ideas have no merit, according to your own analysis.
- Reported for improperly using the report function.
gkam
Thanks.
obama_socks
LOL I find it interesting and humorous that Cap'n StumpRump regards you (and others) as a "troll", while at every opportunity the Rump Captain can't seem to help herself in paying an enormous amount of attention to you, no matter in which thread you have made comments.
There must be a psychological description for such an action and motivation on Cap'n Rump's part of her/your relationship.
Dunning-Kruger may also apply to Cap'n Rumpy's obsessive demands for substantiation/evidence as though she is a college professor conducting a test/examination where "trolls" will be given grades A+ to F for Fail.
And yet, Rumpy can ONLY quote from Wiki and other Search sources while offering links to what she has learned so that "trolls" can also learn from the same source(s). You are feeding Rumpy's huge ego, IMO
obama_socks
It appears that Cap'n Rumpy's high-flying ego soars only when she has found someone to belittle, curse out, and "dress-down" for failing to pass her "tests".
But I also notice that you, gkam, are encouraging Cap'n Rumpy's trolling habits while she pretends only to care about the science. Rumpy, as well as Otto and Ira are trolling YOU, benni, bschott and antigoracle, mainly. They can't abide your presence in these forums. You give them discomfort with all your talk of having degrees and various accomplishments.
There seems to be no solution to this silly nonsense.
bschott
The only way for me personally to avoid the silly nonsense is avoid commenting, and simply expect it when I do. Most of my comments center around the purely mathematical nature (no observational proof other than inferred effects) of theoretical astrophysics. Usually I am told by someone who considers themselves an authority, how the math verifies the assumptions.
You can't debate against anyone who employs that kind of logic (or their devout followers who lap up everything they say)....you can mathematically describe ANYTHING....real or not.
Most of them cannot see how rediculous the picture is that their equations are painting because they can only look at part of the picture at a given time and they hate when a simple example shows a big the holes are.
bschott
Question, how does DM remain in a halo when it is immune to thermal influences and is thus far only inferred to act as a source of gravitational attraction? In other words, what keeps it all apart? The only repulsive force in the standard model is factored in as thermal pressure....
Look at how many crazy theories have made it through peer review based on a proposed DM generated effect just because the math can be made to work out.
Bottom line, unless I actually feel like a mud sling fest it's easier to just sit back and laugh at the lunacy. Now I think I'll mosey on over to the comments under the 2nd law thing and laugh at how they all admit the fourth dimension is a mathematical construct and claim the universe is a closed system because although we haven't seen "the edge" of it, we can hypothesize as an outside observer.
wduckss
"Rings on Pluto? Quote from the article in 2013: Until some other opportunity, maybe already in the spring of 2015, when the New Horizons mission will have reached Pluto, to convince us that it does not have rings. The calculations are clear: slow speed of rotation around its own axis, small mass, and even though there is very favorable low temperature, there are no rings. but, it is needed to point out that the values are contiguous, which is demonstrated by the mass of its satellites. Related to their home planet, they are in terms of mass by far beyond the average of the Sun and other planets 8. " Comentar to:http://www.space....comments etc., etc.
Noumenon
You're the biggest disruptive troll posting at phys.org,... with your multitude of troll-rating accounts...
..........NiteSkyGerl, antigoresockpuppet, fckthierreyhenry, BongThePuffin, john berry_hobbes, maloderousmiscreant, YoureAPeanut, GoshURStupid, tooty, jim_xanara, AGreatWhopper, chileastro..........
all mass troll-rating my posts irrespective of content going back 6 pages, as in the following thread with factual posts.........
http://phys.org/n...ite.html
This is not a scientific journal. Use the ignore option, or stop interjecting your off-topic disruptions yourself into the thread.
Phys1
Math never does. It turns assumptions into predictions, which can then be verified or falsified by observation.
Add to that Pauli exclusion.
Besides, stars actually _do_ gravitationally collapse resulting in white dwarfs, neutron stars, quark stars , who knows ...
Inertia.
If the math works out and the predictions are falsifiable but have not yet been falsified, they _should_ pass peer review.
bschott
Explain. Since it can only be gravity that imparted the inertia on the particles. Or is the theory that they were "created" and entered into the universe already in motion?
Phys1
Gravity does not impart inertia on matter.
physman
Instead these Dark Matter particles would just fly towards eachother due to the mutual attraction and then just fly off into the distance with all their energy in check.
Edit: this is an invigorating read!
https://medium.co...ig1wet4v
Phys1
bschott
I was more wondering how they manage to stay away from the large gravitational fields of the massive objects we can actually see. Without a production mechanism to renew itself, after 13.5 billion years of only being pulled towards the largest gravity field in the vicinity, how is there a "halo" surrounding the galaxy. Eventually, because thermal repulsion wouldn't stop it, all the particles would have to end up in clumps in the centers of stars.
bschott
How does matter that only reacts gravitationally gain inertia in the first place?
Gotta go lads, looking forward to picking back up tomorrow.
Phys1
The DM falls in, gains speed, comes out on the other side with exactly the same kinetic energy. Newton's second law in operation in the presence of gravity. The DM particle does not lose any energy, nothing changes, hence inertia.
How a halo results from this nobody knows, yet.
RealityCheck
Phys1, what you just pointed out is what I also pointed out long ago. That is why 'exotic' (ie, non-electromagnetically interactive) DM is NOT logically/physically tenable hypothesis for (observed) galactic Rotation Curves and (alleged) 'exotic DM' 'clumps/toruses'. Add the alleged cosmological 'expansion' claimed, and 'exotic' DM should be totally dispersed in equilibrium by inertial/kinetic SEPARATION into a diffuse 'gas' everywhere with no 'lumps' in it (for the very reasons you just iterated; and which I also have been pointing out for years). Add also recent/increasing discoveries of ORDINARY erstwhile 'dark' matter in many forms, plus my pointing out the NON-Keplerian orbits within spiral galaxies being still MIS-interpreted as 'needing exotic DM', and you can see just how UN-tenable all that 'exotic' DM interpretations/claims/excuses are in reality.
How long do you think it will be before mainstream 'papers/articles' self-correct? :)
Phys1
I have to change my statement.
The wikipedia article on DM halo formation suggest that "virialisation" is the mechanism. This must means repartition of energy through gravitational interaction.
https://en.wikipe...er_Halos
RealityCheck
Don't sell yourself short, mate; your initial statement was spot on. If you read your wiki reference closely you will note that no actual 'mechanism' is identified or explained, only 'labeled' as 'virial'' but without logical/physical basis for how and why such initial perturbations should not disperse due to cosmological expansion and lack of e-m interactions which would slow their initial inertial speeds (just as you stated).
So your point/statement remains unchallenged. That wiki merely makes a vague claim of "virialisation" but does not actually explain how that comes about and persists in the face of expansion/dispersion as you earlier observed. Moreover, the Cold DM hypothesis has recently been challenged by the Hot DM hypothesis after simulations (by one of the 'fathers' of the Cold DM hypothesis) which show similar cosmological distribution 'results'. But in any case, no 'exotic' DM is tenable (for reasons you and I together have pointed out above). :)
Phys1
To me as a physicist it is clear what this means. It means that gravitational interactions between hypothetical DM particles are enough to cause halo formation. You are correct that the present formulation is vague to the less specialised reader. This should have been made much more explicit. Halo formation probably also means that DM is absorbed by the central black hole, although this should be an extremely small amount due to the tiny dimension of the BH.
sizzlerjoe11
Matter reacting to gravity, being pulled towards it, gains speed, more inertia.So gravity does add inertia to matter. Matter has it's own attraction to gravity as well. There just needs to be enough gravity in the first place.
Phys1
The expression "more inertia" has no physical meaning as inertia is not a quantity.
https://en.wikipe.../Inertia
bschott
Not to mention that all that "gravity" moving "through" sources of gravity doesn't displace ANYTHING, and instead somehow acts as a pretty tight "holding mechanism" on a galactic scale.
I guess we can chat again when all the bugs are worked out.
Phys1
I retracted that statement in favour of virialisation. So don't quote me without also quoting the retraction.
bschott
Virialisation is not a mechanism, it is the mathematical solution for Halo maintenance, and is a great way to try to smooth the math for the overall halo structure, but as DM is theorized to gravitationally interact with massive bodies as you say ( elastically boucing back and forth through them), the lack of any type of displacement observed in those bodies suggest no DM interaction.
There have been several papers written about the "roundness" of the sun. That roundness would be impossible if DM was continuously interacting with it as it is theorized....
Perhaps DM collisions in the core provide the energy for fusion which is why we can't get it to work here....just kidding.
Phys1
Correct, it is the consequence of a physical coupling of the DM particle motion, in case by gravity. The strength of the coupling determines the time scale over which the virialisation takes place.
It is not mathematics it is thermodynamics.
You can not draw such conclusions without a detailed prediction of how large such "displacements" should be and without an observation showing disagreement with this prediction.
Phys1
You probably mean flattening at the poles?
This statement is very far from the truth. There is no way that DM would cause deformation of the sun, but surprise me.
AlbertPierrepointOBE
that the most brainless comment
On this thread
Is from CD85!
bschott
Thermodynamics.... "matter" immune to EM interaction is affected by thermodynamics...OK.
We are talking about the sun...not earth.
http://news.natio...ce-nasa/
We are talking about DM, ANY conclusion about it is speculation at best.
See above link.
Are you drawing a conclusion? Need me to link to a theory where gravity causes deformation of an object? You told me how DM interacts with massive objects, do we see fluctuations in the mass of all bodies due to DM constantly entering and exiting them?
Lots of holes to fill in.
Phys1
Why, I am talking about the sun.
"the Sun is a near-perfect sphere with an oblateness estimated at about 9 millionths"
Oblateness means flattening.
https://en.wikipe...attening
Conclusions are not speculations and vice versa.
Be more specific.
Yes. Even the planets do not deform the Sun, let alone a uniform very sparse DM distribution.
"The tidal effect of the planets ... does not significantly affect the shape of the Sun."
https://en.wikipe...wiki/Sun
Phys1
No need. I know that the gravity of the Andromeda system deforms your nose.
Make falsifiable predictions if you want to make a case.
You yet have to expose any.
Surprise me.
Phys1
bschott
You use a thermodynamic equation to mathematically describe the structure supposedly created by a theoretical (as of yet unobserved) particle who's only definite property is that it does not interact electromagnetically.
There is no observation of it interacting with anything except via inferred effects, only supported through math. It only reacts gravitationally, has inertia, yet you claim the inertial motion was not imparted by gravity.
You apparently don't think gravity can deform anything except for my nose and you contradicted yourself or several times above regarding the hypothetical properties of DM, yet you claim to be a physicist.
bschott
So it only interacts with gravity and via gravity and it moves but gravity didn't do it....hmmm
Without EM interaction, how is supposed to collide with ordinary matter?
No EM interaction yet thermalisation occurs...
What is the unit of measure of a quanta of "gravitational radiation"?
I predict that before either of us dies, the current version of the standard model will, along with all of its "phantom" components which currently only manifest as math holding it together as a theory.
If you don't acknowledge the holes, you fall into one, see above.
Captain Stumpy
see first paragraph below, and then read under the header "Our flatter sun"
http://www.space....led.html
*the particle* is unobserved
it's *effects* are observed which is where the whole DM theory comes from (and why we're testing various methods for specific identification of said particle with falsifiable predictions) did you leave some important stuff out of that post?
you predict it will what?
and if your talking eu, remember eu is already falsified
this is like the FDA/mag-cancer conversation we had - how can you support something that has no evidence but anecdote?
cantdrive85
Well, both you and wiki are out of date and as usual, wrong.
http://phys.org/n...sts.html
Odd that a physicist would rely so heavily on wiki, more of an arm chair "physicist" I suppose.
bschott
Read carefully:
quoted as typed for the lazy reader.
As usual.
Not even close.
Observe it work repeatedly.
Also a funny question to ask in a discussion about an imaginary substance who's existence you support. But hey, irony is usually lost on the mentally inept.
So is the standard model unless you buy into the mathematical kludges used to attempt to keep it valid. Above you have a self proclaimed physicist who can't even see the contradictory nature of the answers he HAS to provide to simple questions regarding motion.
bschott
cantdrive85
Ummmm, not even close. Please link the peer-reviewed paper which specifically falsifies the EU theory. No pseudoscience blogs from "Pith ball" Timmy Thompson or some other acolyte of the dark sciences. Only peer-reviewed papers which specifically addresses claims made by EU. With all your constant claims this should be easy enough even for you.
Phys1
There are too many misinterpretations and holes in your ideas to repair in a post. You should study physics or give up.
Phys1
Nothing is out of date neither in PO article nor in the wiki article. They agree on essential points. Had you read on to get to the scientific reference at the end, you would have seen that the wiki page is a good introduction to the picture emerging from the latest greatest research. Unfortunately, narcissism prevents you from acknowledging science of which you are incapable and profoundly jealous. Check with a psychiatrist if you do not believe me.
bschott
There are too many contradictions in your posts which you ALWAYS fail to address and then need to attempt to end a discussion by saying something like the above. Fortunately anyone taking the time to read your comments, then my responses can see this. If your physics education produces the above responses when challenged, you should study something less difficult for your brain to reconcile.
You apparently cannot even understand why "NO EM interaction"...then using thermodynamic smoothing equations or terms such as thermalisation cannot physically apply to something that doesn't interact electromagnetically...plus you actually said it collides with ordinary matter after saying it passes through stars.
You either need to pay more attention in class or pursue a different career. Or what they are teaching you is....suspect.
Good luck.
Phys1
you are just echoing my statement.
thermodynamics always applies. all it requires is an interaction.
gravity fits the bill. em interaction is not needed.
you raise so many controversial points that it would take too much of my time and energy to react appropriately.
one point at a time is good scientific practice.
Phys1
It is _you_ who needs help. You don't have enough knowledge to address the issues that you address but you fail to see this.
So good luck with it.
Phys1
Echoing is troll behaviour.
bschott
When you make a controversial statement I point it out, it is not me raising these points, it is the logical response when questioning what you say.
It's stuff like this, you cannot apply thermodynamics to theoretical particles if the basis of your theory has the defining property of the particle as completely EM transparent. A particle which only interacts via gravity cannot experience any repulsive force from anything, any temperature keeps things apart.
Particles which only interact via gravity and are in motion MUST have acquired that motion due to gravity, you flat out said they don't.
Clearly not. I obviously have enough knowledge to force you into dodging the issues with what you say. Then trying a cop out troll remark.
bschott
Your favorite source:
https://en.wikipe...dynamics
The first line of the definition immediately exempts these laws from applying to DM, based on the main property (complete EM transparency) the particle MUST have if it exists. If you are telling me the equations you are being taught to model DM interactions are based on thermodynamics, and you don't see a problem or a contradiction here, you, and the rest of mainstream theoretical science is beyond help.
If you are math adept and only claiming to be a physicist or a physics student, then these enormous gaffs, coupled with some math related comments i have seen you post make a lot more sense.
Meaning you have just showed up here to try to troll people who don't believe as you do. If that is not the case then address the issues with your comments, or enjoy being a math adept captain stumpy....at least you'd have one quality saving you from just being useless.
Phys1
I would like to stress "or".
There is no contradiction.
Gravitational interaction can produce equipartition of energy.
Phys1
As I said there are so many controversial statements in that post that any discussion will diverge even further and no conclusion of even clear positions will result. One issue at a time or else I "cop" out.
bschott
Anything with a measurable energy level in the EM spectrum.
Until you put the word "dark" in front of matter and define it as mainstream physics does.
DM has no energy content. That's it's defining property. Are you saying that in order to model it you have to use equations which apply an energy to it? Are you saying Gravity imparts energy to the particle? There is no mass/energy equivalence for DM because it has no energy, and technically no mass. A DM particle is literally a moving "hole" in space that somehow has the property of gravity.
You can't describe DM in any way other than the math you use to model it, and you use formulas based on matter interaction to do this so you keep inserting terms which cannot possibly apply to DM.
I can see why you're confused.