This four-image NAVCAM mosaic comprises images taken on 26 October from a distance of 9.8 km from the centre of comet 67P/C-G – about 7.8 km from the surface. The corresponding image scale is about 66 cm/pixel, so each 1024 x 1024 pixel frame is about 676 metres across.
Changes in perspective and shadows due to rotation and translation of the comet and spacecraft with respect to each other seem to be limited across this particular set of four images, which is why we’ve decided to present a mosaic this time. The mosaic covers roughly 1200 x 1350 metres. But as usual, we urge you to be cautious in over-interpreting the mosaic: the individual images, presented at the end of this post, provide the ‘ground truth’.
Four image NAVCAM mosaic comprising images taken on 26 October. Credits: ESA/Rosetta/NAVCAM
This scene focuses on the same part of the comet as seen in the 18 October image set, but you will notice some interesting new features, as well as some previously visited areas in a new light. (See CometWatch 8 October and the OSIRIS image of 6 August for additional context.)
Visible towards the upper left is a region of brighter material that was previously cast in shadow in the 18 October image, and that appears to lie at the base of a cliff. Some additional bright material is seen at the top of the cliff. This material may be freshly revealed and yet to be covered in dust, perhaps as the result of a recent ‘landslide’. It remains to be seen what its composition is, but no doubt the science teams will be looking out for its signature in the remote sensing data.
Remember though, that this material isn’t in fact bright white on the comet; comets are blacker than coal, and the NAVCAM images are grey-scaled according to their brightness with additional contrast adjustments to bring out the full range of features (see NAVCAM’s shades of grey for a full recap of the way in which intensities are displayed in NAVCAM images).
Also not seen previously in this much detail are the two boulders just below the centre of the mosaic, one of which takes on a heart-shaped appearance from this angle. Zooming in reveals hints of a layered structure and both objects seems to be appearing from beneath the dusty layer, just like some of the smaller ‘boulders’ around them.
Finally, over on the right hand side of the mosaic, the region cast in dramatic shadow on 18 October can now be seen in much more detail. And don’t forget the boulder Cheops and friends above the centre of the mosaic too!
Discussion: 121 comments
Bonjour.
Image très impressionnantes, d’autant plus en apprenant que la surface est plus noire que le charbon!
Pourquoi n’y a-t-il pas d’image d’Osiris. Sont elles plutôt hors du champ de la comète.
Vous est-il possible d’accompagner les images d’une échelle sur l’image. La résolution ne m’aide pas à me faire une idée de la taille des structures?
Bonne continuation.
To interpret this mosaic I need a lot of faith on past photos of this site.
Too much influence from Robin’s views. Seeing ‘hazing’ over the ‘whity’ areas center left of
https://blogs.esa.int/rosetta/files/2014/10/ESA_Rosetta_NAVCAM_141026_B.jpg
How do you account for these layered structures [https://i.imgur.com/Jr4OFQB.jpg] ?
Hi Ivan. Both images present layers vertical to the surface. Logan’s point of interest: Go back a little. As in the ‘dust’ or ‘sand’ you can see ‘drawings’ here. The drawings follow a horizontal pattern. ;). I interpret as ‘at least two’ forces at play.
And don’t forget the VanDerWaals? forces.
Are these drawings formed long back or a recent one. if it is recent is it because the comet is approaching perihelion, gets more heat which causes the layers beneath the dust/sand to move. and the sands arrange itself to take the shape of the edges of the top layer.
Hi Atom. There are slight ‘clues’ saying that this is ongoing phenomena.
https://blogs.esa.int/rosetta/2014/10/22/cometwatch-cheops-neighbours/?replytocom=101644#respond
@ 300 million miles from the Sun??
The top of this mosaic brings back that ‘feeling’ of a big thing assembled of layers and layers of cardboard and Styrofoam nuts.
67P is ‘getting rid’ of his ‘winter’ coat.
The question is how long has that Winter been, 4 years, or 4 billion years?
‘Tepui’ morphology at bottom right of
https://blogs.esa.int/rosetta/files/2014/10/ESA_Rosetta_NAVCAM_141026_C.jpg
Erosion agent not being rain, but sublimation.
‘Tepui’ differential erosion intensified by ‘Laktritz’. Other agents of differential erosion pending 😉
diferential erotion intensified by STATIC ‘Laktritz’ small patches.
‘tepuis’ are born in ‘mirrors’ created by traveling ‘lakritz’ plaques.
Remember the ‘mouths’ of the ‘worms’ in the movie ‘Dunes’?
Anyone have seen structures looking like that?
The dust area looks to me as if its been ‘shaken’ and the dust has slumped in parts of the area. the lines surrounding the areas show a definite pattern like rings on water that is disturbed.
I still feel that there is a vibration effect but at a very low level, perhaps like an earthquake but of low order?
Not all the time but maybe periodically and could explain how rocks and debri fall of the cliffs.
Clive
Quite interesting signaling, Clive.
“…pattern like rings on water that is disturbed.” Sporadic at least, there should be ‘something’ flowing below there that makes displacements easier, besides the ‘rumblings’. 🙂
Fantastic, thank you! I am not able to view these exotic scenes without wishing Chesley Bonestell was here to see them too.
Is there a listing of publications coming out of this project?
As the south pacific legends goes. You can add your own layer to the pearl.
Another teasing picture and the knowledge that there is a lot more to see in the Osiris pictures i will start to colorize my copies in a touch of pink. I think its about time to release a picture of this comet with a detail recognition the available ten-factor better the the navcam.
Thanks again Emily the contrast between the 8 days is nice to see.The different lighting limits comparisons, but Cheops is well lit in both images. In this later image the bright area on top of Cheops does seem to have got bigger, there is less dust.
Apologies to Logan for my “influence”. That point on the cliff is the largest and brightest area we have seen and all the broken bits at the bottom of the cliff all have very shiny faces and most are producing plumes of gas. A rough estimate is the cliff edge has fallen about 15m on a world with a tiny amount of gravity. Terminal velocity is about 1m/s. A lump of “rock” falling that distance on Earth might break into a couple of smaller lumps when it hits the ground, on 67P it would barely notice the impact. Yet we see that the piece of cliff has shattered into hundreds of pieces. In fact we see this everywhere, hundreds of pieces of shattered “rocks” and “stones”, scattered rubble of all shapes and sizes at the base of cliffs and slopes. The material of this comet is brittle and shatters readily, it can not be Rock!
Henceforth I shall refer to the solid surface material as ICE. Its very, very dirty ice, but ice nonetheless. It is black all the way through, so slower processes of erosion have little effect on its appearance, however a fresh fracture exposes fresh ice where radiation has not had chance to complete the blackening process.
The layering horizontally I have a theory for, but the vertical layers seen at the bottom of Image A have me temporarily stumped. Bob the Builders wall seems to have fallen over and is no longer quite so dead straight. Such is the confusion created by 2D images. The fracture to its right with the pits and holes was hidden mostly in the shadow before. It looks like a more advanced version of the fracture and dents seen on the neck plain. Lots of cliff slippage in Images C & B.
Lastly the dust waterfall at middle bottom of Image A. I have seen little skinny short dust waterfalls elsewhere, but this is the biggest one yet.
I have been banging on about this being a volcanic landscape, so I have found this picture of freshly solidified lava on a volcano in Idaho. It exhibits different types of lava and looks eerily similar to the surface of 67P, if a little less worn by the passage of time. Food for thought I think.
https://www.flickr.com/photos/124013840@N06/15040676204/
I think we need to discuss your interpretations. I see the brightened edge of the cliff, I see the bright “rubble” underneath it, but where are you getting “plumes of gas” being produced? If your mind was already biased into searching for sublimation, I don’t believe there’s anyway you would come to that conclusion.
If sublimation occurs at all, it’s in tiny scales produced from ices of molecules formed In the coma. The nucleus appears volcanic with olivine and silicates because it’s constantly being eroded by discharging, and some of the dust is attracted back to the nucleus electrostatically.
This is not my website but please visit for laboratory experiments of discharges producing all of the craters observed on 67P and planetary bodies.
https://www.setterfield.org/crater_origins/crater_origins.html
Electrostatic discharge could very well be one of the processes taking place on 678P pulling in dust from sublimation and ‘reattaching’ it to 67P.
See the link for some NASA information regarding an electrostatic pulse bathing the Cassini spacecraft as it passed Hyperion, one of Saturn’s moons.
https://spacefellowship.com/news/art41490/cassini-caught-in-hyperion-s-particle-beam.html
Hi Wayne. So, Hyperion could end being nothing more than a captured pristine comet.
Any spectrographical relation between Hyperion and Rings?
Hi Robin. Your comments an other’s are of the most importance by your scientific background. I’m just a science fan, uneducated. I read all of them and do my best to understand you. I wait -sometimes days- in order to thread something that make sense. But on making my own treads the strategy at this early days is wild ‘creativity’. I’ll come back and laugh a lot.
Logan your wild creativity and cryptic messages have been a source of much inspiration and clues to me. I try to understand your thinking and garnish it with some plausible science. As I’ve said before, I’m making it up as I go along. There is no rigour to my arguments and many have pointed out the inconsistencies and errors. In this arena a hypothesis only has to be one step from a guess. Mine are little more than vaguely educated guesses in my estimation. I find it a process of learning I quite enjoy. So many people have little nuggets of insight.
Leo has tagged it as ‘black ice’. Would like to know a lot of math and theoretical physics to understand his model.
“…black all the way through”. Black, not blackened.
“…a fresh fracture exposes fresh ice where radiation has not had chance to complete the blackening process.”
Taking it into my hat with the reserve of it being ‘core’ material.
Logan’s def: ‘core’ is the material still in the original place assigned by the accretion – grow process. It’s very old material. It is not the original chemistry, nor the original structure.
There’s a scene in the first Austin Powers movie, the one where Dr. Evil has captured Austin Powers and is about to feed him to the sharks. Dr. Evil’s son keeps telling him that look, I’ve got a gun in my room, I’ll go get it and pop, it’s done. But Dr. Evil insists on taking the most questionable course of action in disposing of Austin Powers, because that’s how it’s always been done, and you simply don’t question how things have always been done. It closes with a funny scene where Dr. Evil keeps “shushing” his son each time he tries to talk because he absolutely won’t consider any other alternative. He’s completely locked into his view no matter how unrealistic and even ridiculous it may be.
Now Robin, you’ve presented some great insights in this forum and have effectively moved discussion forward despite an oftentimes glaring lack of tangible scientific disclosure from ESA, and I for one much appreciate your input. So no disrespect intended at all, but it’s borderline shocking to me that someone who’s obviously quite intelligent can be so ingrained in a belief that so clouds the evidence of their own eyes that they would declare an object that for all intents and purposes looks exactly like a big rock as “very, very dirty ice.” Seriously? Do you have any hard scientific data backing this assertion? Or is your assertion based on a belief that is then based on an almost religious faith in mainstream astronomy’s sacred dogmas, and you absolutely won’t consider any other alternative not in line with that dogma?
I’ve been closely following both mainstream astronomy and electric universe theory for over 5 years. I love astronomy, but truth be told, I’m just as fascinated to be witnessing the interplay of human dynamics that are unfolding as these two theoretical models collide. It’s a classic establishment vs rebel melodrama with absolutely profound and world changing consequences as fundamental as “is the earth flat, or is it round?” With that question, back in the day, you had hard core dogma rooted into the fabric of society that would not tolerate being questioned or allow open discussion of its merits and drawbacks. It takes incredible upheaval to unseat established beliefs, attitudes, power and funding and educational structures, establishment heros and reputations with lifelong training and dedication to their professions, and a social world view based on decades of indoctrination by “experts.”
And make no mistake, EU theory is a game changer just as fundamental and titanic as the flat vs round question was. It literally rewrites everything, and overthrows virtually every sacred cow in astronomy-dom such as the big bang, red shift, black holes, black matter, black energy, etc etc…oh, and dirty snowballs in space.
So, I’d like to invite you to at least investigate EU theory to see if it holds merit. It’s not as sexy as the exotic speculations born within the human imagination that defines mainstream astronomy, for it’s based on known, proven, demonstrable, replicable and predictable properties and dynamics, which I guess is what real science is about after all. But it’s implications, if true, are incredibly exciting, because it’s an opportunity to see everything in the known universe with new, and perhaps better informed, eyes.
Unfortunately I only know what I know. I am intrigued by this EU model but at present I have yet to be convinced by any arguments made on it’s behalf. Statements such as “It looks like rock, therefore it is rock” are to me and my scientific training, irrational and completely absurd. If this represents the level of proof that is taken as sufficient to verify this theory, then it is a theory without any realistic hope of credibility, let alone applicability.
Others here have taken a less dogmatic approach and are willing to see some more realistic evidence before dismissing it. I have watched the Thunderbolt video posted on this blog earlier and read the articles suggested. There are a lot of unsubstantiated claims, circular arguments, cause and effect are used to justify each other. This is not science. Just because it is anti establishment, counter to all current theories and presented as science, does not validate it in any way.
Yes I agree with those who say we should not meekly accept current theories, that is the strength of the scientific method, nothing is sacrosanct, but the world we live in today is based on the real and practical application of those theories. They work and are proven to be applicable to create the technology we use today. Computers work because we understand Quantum Mechanics, GPS systems work because they use General Relativity to account for the effects of Gravity.
This is a theory that only proves what it wants to prove, in this case a comet made of rock. It is in effect just a self fulfilling prophecy applicable only to imagined scenarios created just to prove the theory. If some want to believe an incoherent and and irrational series of claims that serve no purpose other than self promotion and deliberate provocation, then they are welcome to do so. I have learnt what I need to know about this theory and have made my judgement. If in 20 years I am proven to be a fool, so be it. It has ever been the case, and will continue to be so as science advances.
There is simply no need for sublimation to produce what we observe. There is zero water ice on the surface, not black ice, or dark ice… no ice. Not a trace. All evidence of sublimation has arrived through indirect observation, such as the presence of hydroxyl in the coma, which was assumed to be caused by the photodissociation of water. But we have direct evidence of hydroxyl and water being produced on the moon via solar wind interaction, the exact same process put forward by EU proponents.
EU proponents argued that planets and moons are negatively charged bodies. Charged bodies in a plasma environment are going to undergo electromagnetic phenomena as they will produce electric and magnetic fields. This was proved to be a FACT by the Cassini mission, who then predicted other moons, asteroids, and comets would be charged.
My biggest problem with established science is the dismissal of refuting observations. Deep Impact produced a crater much smaller than predicted (because it’s a rock, not a coalesced pile of dust) and speculated that some of the dust after impact must have fallen back down, refilling the crater and making it appear smaller than it was. This is ridiculous since jumping from the surface would exceed escape velocity. Then you have the Stardust/NeXT mission which collected samples of silicates and olivine which could not have existed In the presence of water and were “born out of fire.”
So you have a comet, which is likely a negatively charged body, with zero ice on the surface, traveling toward the inner solar system which has a greater density of ions. In the electrical model, we should expect an increase in activity in the form of cathode etching of the surface (jets producing craters) and production of hydroxyl, water, and hydrocarbons.
The EU perspective also incorporates historical evidence of past civilizations who regarded comets as terrifying, devastating events which rained oil and fire. Sounds like a ridiculous story when you’re viewing a comet as a snowball and not a discharging body.
When you look at the body of work and understand that the observations we were limited to obtaining were indirect, then you’d see how easy it was to make a wrong turn. Sublimation was a fine theory, but when refuting evidence is presented you must be willing to take a step back and reevaluate with no bias. Asteroids which suddenly behave as comets is a great example of the EU offering a much more unified theory and the mainstream tacking on another ad hoc theory.
@Robin Sherman : “Statements such as “It looks like rock, therefore it is rock” are to me and my scientific training, irrational and completely absurd.”
Robin, for starters, you’re not the only one on this blog to have had very thorough “scientific training”.
Personally, I say things like “The images Rosetta was sent to get show stratified rock faces and piles of stratified boulders lying at the base of rocky cliffs, exactly like in many places down here on Earth. I therefore conclude that this comet nucleus, at least, is composed of stratified rock. I further hypothesize that other comet are also composed of rock, especially since this was already strongly suggested by the images we acquired of Tempel 1 (of Deep Impact fame) and Hartley 2, amongst others”.
I am a fervent believer in the scientific method, which starts with observation and continues with pattern recognition, leading to the formulation of a theory which can then be falsified if the initial observations prove to be worthless or if further observations are such as to invalidate the theory. There’s nothing “irrational and completely absurd” about this sort of approach, is there? But perhaps you had a different sort of “scientific training” which was based on something other than the scientific method?
@ Sovereign Slave, great post, I agree with every word. There is indeed a truly Shakespearian dimension to the interplay between so-called “science” and its varying interpretations (“There are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy”)…
To come back to more mundane matters, I would simply add that the EU model we both refer to is entirely the product of the applied research and engineering sciences and has thus been formulated by hands-on scientists whose work is dedicated to finding out 1) how things actually work in the real world 2) how to make them work even better in the real world and 3) what other things can be created and made to work in the real world. In other words, the EU model has NOT been formulated by the pure theoreticians and mathematicians who were at the origin of the ageing standard model and who are (understandably, given what is at stake…) still attempting to defend it tooth and nail against the implications of all the new observations flooding (and not only from Rosetta, by any means).
Perhaps ironically, the founders and main supporters of the EU theory exert the same sort of trade as the whole range of engineers who got Rosetta and Philae where they are, to send back to us these extraordinary ground-breaking images. They are ENGINEERS: they know how things REALLY work rather than how the theoreticians think and dictate they should work.
Whatever, EU theory has always been a matter of applying strict scientific method via the initial observation of actual cosmic phenomena, recognizing patterns of similarity with the way the electric force operates on Earth (whether it be in the invention and subsequent operation of man-made facilities, in the observation of the natural environment, or in laboratory experimentation) and then confirming the resulting theory by further observation of other cosmic phenomena. It is thus not only a falsifiable theory (which can certainly not be said of standard theory…) but it has also been able to make confident and invariably successful predictions about the results and findings of our more recent encounters with comets, including this extraordinary, ongoing one….
What more can you ask for?
Again, sincere thanks and congratulations to all those involved in making the Rosetta mission work and turning it into one of the most extraordinary leaps forward in space exploration of all time, both in terms of technological accomplishments and of acquired knowledge.
It’s going to be a paradigm shifter. That’s presumably why it was called “ROSETTA”, when you come to think about it.
A great hug to all Engineers involved with Rosetta Mission.
So my big unknown now, is those streamers. More specifically, what do the sources look like and how do they shape the appearance of the landscape? The little cups and bowls, the little mud volcanos, the jet engines, rocket launchers, huge caves or the innumerable semicircular features with one steep side and a flat bottom, that cut into any sort of sloping surface and come in all sizes from a metre to hundreds of metres across. The last would be my choice, but the mechanism and lack of any obvious associated fractures in the surface for most, still confounds me. A sublimation scenario looks more likely to explain those.
Bill, streamers/jets are your pet subject, any thoughts?
@Robin= “Bill, streamers/jets are your pet subject, any thoughts?”
We haven’t seen, with our available images, actual venting vents, yet. We have seen that one line of depressions on the North Polar Plain, which is dang likely. We see odd conical depressions. We see depressions in dust on the grooved/lineated rock (best rez Site J pics). And’ I’ll speculate, those areas of “rubble” or scree that are dust-free and fresh looking are vent areas.
Remember, we are now looking at the aftermath of the last perihelion where the silicates and refractory organics settled down after the comet cooled and quit degassing. And we are now at just the onset of activity of this passage.
Front row seats. Yeah! 🙂
–Bill
Hi Bill. Guessing what is an old streamer vent is a fun challenge though. The rocky, rubbly areas are definitely sources of greater sublimation, as are exposed lumps of ice. Sublimation seems to create diffuse plumes and clouds of dust, as seen in front of the cliff below the Amphitheatre in the 24th October image, the kilometres long jets are made by another mechanism.
The collimated nature of those neck streamers is what needs visually explaining. We have images of large parts of the neck plain where they have been seen, but never coincidentally to link the jets to a particular type of source capable of producing this observed focusing of the jets. Round features and possibly short cracks are what I am looking for. The trouble is there are several different possibilities that might fit the bill.
Why do you stick with the sublimation mechanism so intently? It is simply not needed to produce the phenomena we observe. The appearance of the nucleus, structures on the nucleus, and compounds in the coma do not require sublimation, therefore, Ockham’s razor should remove all ice, snowball, and sublimation terms from comet theory.
@Robin: “”The collimated nature of those neck streamers is what needs visually explaining””
Indeed. We’ve seen the jets and hopefully we’ll be able to understand the processes behind them.
Two papers on this:
The Near-Nucleus Coma Formed by Interacing Dusty Gas Jets Effusing from a Cometary Nucleus
J.F. Crifo
Icarus 116,77-112 (1995)
and
COMETARY JET COLLIMATION WITHOUT PHYSICAL CONFINEMENT.
J. K. Steckloff
43rd Lunar and Planetary Science Conference (2012) 2548.pdf
A little light reading…
–Bill
Hi Bill,
Read the second paper, could only access the abstract of the first. The model they used made some assumptions about the composition of the active surface, one of which was Water ice present at the surface. ESA leads us to believe that is not the case on 67P. However they also assume the active region is only 0.3% of the surface area of the comet and the scientists at ESA admitted there was a limit to the resolution of their results. What that was, was not revealed. So as laymen we cannot be sure if their model is relevant.
Despite all that they are suggesting we would see something akin to what Cantalloube described. This I think makes the little circular dents seen on the neck plain prime candidates for the production of jets. It might also suggest areas of semi permanent shadow would be the place to look, where not all the Water ice in the surface has managed to escape. The apparent issuing of the jets from the dark side of the neck, that receives very little sunlight, is in fact the case. We might not see where the jets meet the ground, either because its dark or Rosetta images of this area were not taken due to that darkness. Reflected light from the surface and coma might be the only way we could see them.
A bit of a downer really, we might not ever see the bright jets streaming out of the surface, only from over the horizon as we have already seen.
No matter, I shall just assume for the purposes of speculation, collimation is more to do with the particle size and porosity of the surface. Chemical interactions at those densities and velocities would I think, be negligible.
Gas and dust rushing through the filter of the Laktritz layer, of whatever composition, would be a way to conceptualise the effect. As a practical chemist, I see fluids under pressure passing through filters regularly and the fluid comes out the other side in a central stream, not through all areas of the filter. I’ve always assumed it was a surface tension effect of liquids, usually Water which has a high surface tension, but I have also seen it with Ether, which has a very low surface tension. Not sure what the actual mechanism is, I’m sure someone might know and be able to explain it. So I’m not giving up hope of seeing bright jets coming from the surface and I still think the source area is likely to be basically round, but the actual source hidden by the surface layer of Laktritz.
The upshot of that would be sublimation gases that don’t pass through the porous surface layer will not be collimated and would take the form of plumes and clouds, just as I have seen. Eureka! 🙂
@Robin: “Sublimation seems to create diffuse plumes and clouds of dust, as seen in front of the cliff below the Amphitheatre in the 24th October image, the kilometres long jets are made by another mechanism.”
I don’t agree with you. A SINGLE mechanism is required, which accounts for BOTH observations: EDM (electric discharge machining) is producing simultaneously:
1) what appears to you as “diffuse plumes and clouds of dust”, through the local heat generated by cathode sputtering , and
2) the “kilometres long jets” which are actually the local, visible, dust-laden part of huge Birkland currents which connect the comet to its electric environment (the Sun as anode and the heliopause as cathode).
Nature is lazy. It uses that tiny +/- electromagnetic mechanism to power everything, from the infinitely small to the infinitely large. The behaviour of comets is just one tiny (if spectacular) manifestation of that force among an infinity of others, starting with how the neurons of our brain function….
Makes you think, no?
@ RobinSherman : “Round features and possibly short cracks are what I am looking for.”
You mean apertures like the nozzle of a garden hose? Thousands of them all over the comet surface? If it is simply the mechanical phenomenon you seem to be suggesting, being driven by extreme internal pressure of mysterious origin, how do the “ejecta” shoot out in such dead-straight lines? What force could possibly collimate them over kilometres, as observed ?
Hi Bill. “…Remember, we are now looking at the aftermath of the last perihelion. Fully agree, For the most, we are still looking at the ‘after-party’ 😉
Excellent commentary, and very good stitch of the images.
This is a comparison with the 26 October images with earlier images, in particular highlighting the area of the “additional bright material is seen at the top of the cliff” and boulders on the Equatorial Plain.
https://univ.smugmug.com/Rosetta-Philae-Mission/Rosetta-Comparative-Series/i-v7ghN4J/0/L/compar_26-Oct-14_images-L.png
–Bill
Robin & Bill,
I dont neccesarily think the Ice/rock has shattered on hitting the ground, in fact in Bills slope failure picture, it could be a large slab has broken off in one piece.
It could just be that the Ice/rocks are dug out of the cliffs as its eroded, this could easily be from sublimation of bits of ice holding all the rock together, or from the coarse scaring of the surfaces electrically.
Hi Dave, I agree not all the rubble etc is from cliff falls, and very large chunks of cliff do seem to hold together pretty well. Some process is splitting the ice cliffs, the lines and scars that criss cross exposed cliff faces are evidence of that. That could just be the 67P equivalent of frost damage, the major source of such rock crumbling on Earth.
If, as I have speculated, there is “ice lava”, there are different types of ice lava, some is solid and compact, some rubbly and loose containing a large amount of fractured pieces of ice, the picture I found illustrates this with a visual analogue of mineral rock lavas. The image from 24th October, top left shows the edge of what I think is one of these rubbly ice lavas and we see chunks of ice, large and small, have just fallen off it.
My point was really that an igneous rock, which this would have to be, Basalt or Granite say, would require an awful lot more energy to shatter and break them than is available on 67P. Of course if powerful electric discharges are present that might be different.
The agreed consensus of the “experts” is that this comet is made of volatile ices. They have studied these things in a lot more detail, with a lot more knowledge and experience than I have, so I am inclined to take their view as the most likely to be correct. The evidence I see, is stacking up to say that they are not far wrong and the unknowns are in the details.
Queue, claims of biased scientists, dodgy data, hidden data, conspiracies, incompetence, ignored theories and all other manner of arguments to refute my position. I’m not the one who writes textbooks or scientific papers, so what do I care. Explanations and theories that satisfy me, thats the only thing I am seeking. Something that I guess is true of the majority of contributors to this blog.
@Robin, @Bill,, in support of ‘freeze fracturing’ is the rubble and boulders of 67p, don’t you think?, plus the patterns of the shifting composition of the coma of Hartley-2 (comparable data should by now be heaped up about 67p, of which this blog know zero) …which together suggests that different polarity / freezing point substances mix considerably less than simple assumptions would predict.
Besides: it seems to me that too much emphasis is put on the sources of the current ’emissions’ the ‘searchlights’ so very faint. In due time we will look back at the activity up to this stage and ask ourselves what all the fuzz was about. By then ‘faint plumes’ may have shifted to ‘violent eruptions’
Besides no. 2: The expression ‘electrical discharge machining’ often stated here distracts (me) from the fact that electrostatics play a role in the fate of small objects (how small I don’t know). What puts me off is idea of ‘welding arch’ producing ‘immense heating’ and sooting. While, on the other hand, the patterns of the ‘searchlights’, movements of dust near the surface, etc. are in some extend surely ruled by netto charge (and mass).
Hi Jacob your note of caution about the relative size of the activity is key. The shortage of any other meaningful data from ESA forces those of us avidly following the Rosetta mission to strain and pour over every pixel of every image that squeezes its way out of the clutches of the guardians of the “holy” knowledge.
The spectacular looking streamers have led to much debate and conjecture. The appearance of these jets was totally expected and for most people it was the one thing they wanted a close up view of. Having shown they exist and are not the product of scientists imaginations, it is natural for those interested to know something about them. Every child shown these images is going to ask “what are they made of?”. I am not even sure if we have an official description of what they are made of. I think Emily and Claudia have inferred that they might be made of gas and dust. Do ESA assume everybody knows that already or it is such a prized piece of information it can’t be revealed. A simple sound bite of explanation would do.
“These jets are made from the vapour produced by volatile ices in the comet and dust on the comet. The processes producing the jets creates a flow of gas at ? Kmph and this carries the dust along with it. The dust in the jets scatters sunlight so that we can see them. The main gases present have been found to be Carbon Dioxide and Water vapour with varying amounts of other simple molecules, such as Ammonia, Carbon Monoxide and Sulphur Dioxide”.
Every scientist in the area of comet research knows this, it is not new knowledge and is not part of some grand new theory of comets. By all means attract new interest with these lovely images, but to then not provide even the most basic information about them to nurture that interest, seems a pointless exercise. ESA can sponsor the making of a glossy, CGI fest to promote the Rosetta/Phylae landing, but can’t seem to provide meaningful and factual bylines not hedged with “ifs” and “maybes”, to the actual images.
@ Robin: « I’m not the one who writes textbooks or scientific papers, so what do I care. Explanations and theories that satisfy me, thats the only thing I am seeking. Something that I guess is true of the majority of contributors to this blog. »
I couldn’t agree with you more, Robin. I’ve never made any sort of living, either, from anything “scientific”. I’m just a “citizen scientist”. (And I simply hate to think how much it’s going to cost society to rewrite the textbooks and retrain the teachers when the evidence being obtained by the aptly-named Rosetta mission is finally deciphered by the experts…).
As for the “explanations and theories that satisfy me”, I’m also completely on the same wavelength: that’s what I’ve been looking for too, over the years, as a matter of pure intellectual satisfaction. I was myself a totally convinced mainstreamer for many decades, up to around 15 years ago, until I began to actually start looking at the pictures for myself, instead of simply swallowing wholesale all the unpalatable (and still elusive) “dark/black” stuff that is served up with the standard theory. I then quickly realized that the shock, astonishment and incomprehension expressed by the experts at each new observation were the signs of a falsified theory.
Since then, I have discovered and now support an alternative model which fully satisfies the expectations I have from the correct application of true scientific method, in the shape of the Electric Universe theory, which is even able to make accurate predictions (as in the case of the Deep Impact “double flash”, to take just one example – there are many more). Making accurate predictions is presumably the ultimate proof of a successful theory, which can hardly be said of the henceforth severely battered “dirty snowball” model….
The meager set of images which have so far been released by Rosetta mission scientists are yet again fully in line with EU predictions/ expectations, right down to those tens of thousands of boulders heaped up at the base of hundreds of stratified, rocky cliff-faces. And, according to mission scientists, not an ounce of ice to be seen anywhere. And no theorized “vents” for hypothetical “outgassing” observed either. Just “jets” shooting vertically upwards, not just from the neck region but from the entire surface of the comet, even from areas on the dark side ….. All this is PREDICTED by EU theory.
That’s why it “satisfies” me!
Nicely put Thomas. I hope you get some physical evidence to show the surface we see is made of rock. Part of me would love to see the complete chaos such a paradigm shift in cosmology might cause. Fudge factors like “Dark Matter”, “Dark Energy” and now “Dark Flow” don’t sit well with anybody in the science community, but hey they need to generate resource funds, so claim something is there, give it a media friendly name, Bob’s your uncle, careers secured for another 30 years or am I being too cynical. One thing is for sure you are never going to have all the answers, it would require infinite time in an infinite Universe or Universes.
Thanks, Robin.
“I hope you get some physical evidence to show the surface we see is made of rock.”
In the case of Galileo’s observation of Jupiter’s moons through the new-fangled “telescope” Galileo had just invented, nobody required that he provide “physical evidence” (which?, how?), the images were enough to trigger a complete paradigm-shift (albeit several years later – the inertia of Establishment thinking always has been, and apparently still is, a dead weight acting to hold back timely progress…). That paradigm-shift still holds good four centuries later, just on the basis of the images Galileo acquired at the time. We’ve simply refined that paradigm since.
I suggest that Rosetta’s images of this totally jagged ,stratified rock surface of what is supposed to be a dirty snow-ball, with tens of thousands of stratified boulders piled up at the base of hundreds of fractured rock-cliff faces will more quickly achieve the same sort of paradigm-shift as Galileo’s rudimentary telescope did over four centuries ago.
“Fudge factors like “Dark Matter”, “Dark Energy” and now “Dark Flow” don’t sit well with anybody in the science community, but hey they need to generate resource funds, so claim something is there, give it a media friendly name, Bob’s your uncle, careers secured for another 30 years or am I being too cynical.”
Not cynical at all, you’re being realistic. The things you call “fudge factors” are what I call elsewhere on this thread “fairy-dust” (in response to pleas from some posters to refuse to believe the evidence of my eyes…). “Dark Matter”, “Dark Energy” and now “Dark Flow” (I would add the original and ultimate modern myth, “black holes” – sorry for this ultimate heresy…) are long-established examples of the “dark” fairy dust which the theoreticians started serving up to us when the mathematicians somehow established their ascendancy over the natural scientists, in spite of all common sense, over a century ago. There is no need whatever for any of these standard-theory-saving-puncture-patches once we accept the EU model: the almost infinitely greater power of the electromagnetic force than that of the force of gravity over astronomical distances accounts for all the “anomalies” which these fudge factors have been dreamt up for by mathematicians, to try to save the standard, cosmological, “Big Bang” theory.
“One thing is for sure you are never going to have all the answers, it would require infinite time in an infinite Universe or Universes.”
I don’t want all the answers, otherwise there’d be no point in carrying on thinking and life would be too boring to be worth living. I just advocate the recognition of basic truths, such as the greater validity of the laboratory-tested EU model as compared with the merely hypothesized and increasingly falsified standard model. We can then finally start to refine the new paradigm to try to get as close to the truth as possible…. For the moment, in the present state of Establishment cosmology, we’re living in Wonderland. Rosetta is helping to bring us firmly back to Earth.
@robin maybe “jets” have a very unappealing aspect when seen at very short distance. I remember having walked into Stromboli crater while it was emitting a wide panache of ashes and gazes. I had the impression of walking on a very smooth ash surface scattered with some basaltic bombs. The tons of ashes emitted were somehow percolating between the ash cover but it was completely invisible at close range.
Of course gravity was much higher than at the comet, and the air pressure may have played a role.
But I won’t be too much surprised if Philae lands in the middle of a jet… and does not see anything more than a faint haze in the sky around…
I am afraid you might be right there. The dusty layer might have enough density and cohesion to largely limit sublimation, but not the higher pressure process clearly responsible for the jets. The surface dust layer is speculated to be loose and porous. The hunt for a more obvious source is more fun though until an explanation is forthcoming.
Good point Cantalloube 🙂
Bad point Philae 🙁
13 days to go…Eagerly waiting to see Philae landing safely on 67P.
Why is it taking so long (Nov 12) to drop Philae as it has entered into the comet’s gravitational field on September 10 ?
why the Philae is dropped from 22.5km? Why can’t rosetta go so close to the comet and drop the Philae? What are the complications involved in that?
Hi Atom. The best answer in my mind at this moment is that several programed experiments need to begin from some distance. Other arguments have been said here, relative to ‘lander’ design an the unusual shape of comet 67P. Precisions and corrections welcomed 🙂
@Atom Universe: Orbital mechanics. The closer you go, the faster is the orbital speed.
In order to land you have to get rid of that speed. Elliptical orbits mean fast orbital speed when close to surface, low speed when at the furthest point out.
So the position to “break” most efficiently is at the greatest distance.
If your thrusters are big enough and you would have a infinit fuel, it would not matter.
Another reason might well be “time for science” during decent.
Philiae might well get lost when it attempts to land. So the longer its instruments can do measurements before, the better.
Might be a mixture of both reasons.
The principle reason is to do with the way Philae is released from Rosetta. There is a variable system which could give the right amount of breaking to Philae from many different orbits. There is a failsafe mechanical system involving a spring mechanism. This has a fixed energy it can impart to Philae and so only one release point in a particular orbit will enable a landing in the desired location. Philae has no method of steering or changing altitude once released. Thus the initial “kick” she receives from Rosetta is the only method of guidance available. The orbital release point has been chosen such that both could achieve the desired trajectory upon release. Rosetta has been in space for a very long time and to rely on one system when two would increase the chances of success, seems pretty sensible to me. Put simply, orbital mechanics, gravity and the fixed amount of energy Rosetta can impart to Philae is the reason. Rosetta must also ensure that communication is maintained and that she can avoid crashing into the comet as well.
There might be multiple reasons for that. One for sure was to check for the best landing site.
The other one is making sure to get as much as possible science before the next critcal step.
You never know what happens during seperation. Sometthing might go wrong, the hole probe might get lost….
So take what you can get before entering the next critical phase.
There might be other reaons, too
Pardon my ignorance if I’m wrong but isn’t the Nav-Cam the wide-angle camera? And, if I am correct, why have we not seen photos lately from the narrow-angle camera?
Hi Robert. Academic contract issues, older that Rosetta project itself.
I do not believe my eyes. I do not believe that I am seeing rocks; the physical properties of the component parts do not add up for me.
We know that P67 has a density of 0.4 g/cm^3. Consider the solid phase densities of some of the known components of P67 (all in g/cm^3): water, 0.93; CO2, 1.5; ammonia, 0.82; methane, 0.45; olivine, 3.3. I propose that the overall low density of P67 precludes the solid aggregation of these higher density components to form “rock” or solid ice.
Consider the things that we know have densities around 0.4, for example flour, 0.6; unsweetened cocoa powder 0.34; talcum powder, 0.27 – 0.4. These are dusty materials.
Comets are composed of interstellar dust, and I propose that P67 is just that, clumped dust. The striations in the cliffs represent gradations blackness of the original dust as it aggregated onto the nascent comet.
Rather than the “Dirty Snowball,” I propose that P67 is a “Dirty Dust Ball.”
Why not a “Dirt Ball with Ice Dust” or a a “Dusty Snow Flake” or a “Snowy Dust Flake” 😉
Hope everything goes well with the landing and we will find out soon
BTW: this recaptcha feature is going grazy. Even if I blow it up so it fills the screen I can hardly read the curvy blurry part………
The density is measured indirectly based off interpretation of the comet’s “gravitational field” to compute the hypothetical mass. Just as Cassini was briefly “attached magnetically” to Hyperion from 2000 km away, the possibility exists that Rosetta is undergoing an electrostatic force which is not represented in the calculation of its gravity, mass, or density.
In other words, believe your eyes. It is a rock, absolutely no ice is needed to produce the phenomena we can directly observe.
@Ross, you have stated over and over that we should believe our eyes. That is what a magician relies on when he fools us over and over. In order to know what the magician does, you have to study his trade. Relying on our eyes gets us nowhere.
Rest assured the calculations of mass and gravity are as accurate as they will need to be to perform the landing procedure.
One question I would like any EU proponent in here to consider is this: how can Rosetta and all the delicate electronics be in a working condition when it has perfomed the same elliptical travel around the sun as has 67p? Where is the immense heat, welding arch, etc, eating away at Rosetta?
@Jacob nielsen. I too have stated the same thing as Ross in terms of believing what our eyes are telling us. Why do you think we spent a billion dollars sending Rosetta to have a very close look at this comet nucleus if the pictures it acquired were always going to be trashed as pure illusion anyway?
You can believe whatever your pet theory dictates to you, that’s your problem. Personally, I believe my eyes in this case as I have done in my every waking moment for over 60 years: so far, my eyes have stood me in good enough stead to correctly interpret the world I live in. I don’t see why I should suddenly start thinking they’re lying to me in this particular case just because Fred Whipple coined the “dirty snowball” term 60 years ago on the sole basis of pure theory and absolutely no photographic evidence. There are no magicians on Comet 67P/C-G, your analogy is invalid.
As for the intense heat, it is melting the rock, as in arc welding, but that heat is obviously immediately dissipated in the near absolute zero temperature reigning just a few centimeters (or even millimetres) in the total vacuum above the surface. (That is also why, as will soon be confirmed, those smooth surfaces seen all over the comet are in fact vitrified, like lava, as the molten rock immediately solidifies when the focus of the electric discharges moves on and the molten rock literally freezes immediately). Rosett, at around 10000 metres away, obviously runs no risk whatever from that heat, just as the welder is not burnt to a cinder by the heat generated by his arc.
Where is the problem?
@Jacob nielsen, the “magicians” you refer to are not up on the comet but down here on Earth. They are the defenders of the falsified “dirty snowball” theory who are still attempting to persuade people that they shouldn’t believe the plain, rock-solid evidence which is there for all to see, but instead the fairy dust theory they are still attempting to blind us with.
I don’t believe in magicians and even less in their fairy-dust.
You do not see the comet with your eyes, you only see pictures of the comet, pictures that have not the best of resolutions and from a distance of over 7 km away at the best, the ESA wizards have pictures that are 60 times better concerning detail recognition but will not show them so far. Who is fooling who?
The problem is: Why is the comet so charged in a way that it can melt rock, but Rosetta, following a similar path through space, is not.?What makes Rosetta immune to the electrification? What sort of voltages are we talking about? 1kV? 1GV? Between what points on or near the comet should we expect a potential between? Do we expect to see the actual “arcs” as super bright points of light, like a welder? What Philae results are predicted from EU theory?
Specific answers to these questions may make EU falsifiable. EU, at the moment is completely subjective and descriptive, rather than objective and quantified. I think even the subjective aspects are wrong enough that EU theory will be severely challenged to even stay relevant in the long run.
@Cometstalker: “Who is fooling who?”
Your guess is as good as mine.
Personally, I can’t wait to see the close-up images either. IMHO, we should be seeing evidence of extreme heat at the base of those “jets”, a bit like at the base of a welder’s arc. They must even be visible to varying degrees all over the surface of the comet (and not just on the “whiter” parts of the neck region).
Too hot to handle in the present state of affairs?
Jacob nielsen, you need to understand that the charge carried by bodies in the solar system is governed by their position in the heliosphere and their interaction with other bodies. The comet 67P experiences a constantly changing state of charge throughout its elliptical orbit. It is now returning from beyond Jupiter where it would have acquired the charge of that region, opposite to that of the Sun. The Rosetta craft on the other hand departed from Earth with the same charge as the surface of Earth. In its approach to the region of the comet it would have slowly collected the charge state of that region. But not exactly. And not exactly for the comet either as both are continuously moving within the charge gradient. They are not therefore stable but in a state of stress. Now they are both moving towards the Sun both are discharging and will do so at an increasing rate. The reason the metal of the Rosetta craft is not sputtered like the rock of the comet is because it reacts differently to the proton stream from the Sun. The current density would need to be much higher to damage (ionise) the metal. The existing current density is however enough to affect the functioning of the instrumentation. Hopefully when the lander touches the comet they will already be similarly charged, otherwise there could be a violent discharge. The relatively slow approach of the lander should allow them to become balanced and avoid this. An important aspect of this experiment is to see what effect the discharge current of the comet has on Rosetta and the lander. Also what effect the overall discharge has on Rosetta and the separated lander as they approach the Sun.
@John, I was about to answer Jacob nielsen along much the same lines. No need now, you summed it up perfectly!
My fear for Philae, if it does ever manage to successfully approach the surface and land in a more or less upright position on a fairly flat area and anchor itself down (already a lot of “ifs”…), is not that it will be shorted out directly by an electric spark between itself of the comet, either during the descent or the landing. The phenomenon of equalizing charge balance between the comet and the lander which John has so clearly and concisely explained would seem to preclude that. (But it’s not impossible, either, since we yet have no idea of the actual voltages generated by the charge differentials involved).
No, my fear is rather that Philae will instead suffer equally devastating COLLATERAL damage due to the ongoing electric discharges caused by the considerable charge imbalance between the comet and the WIDER electrical environment (otherwise, on a less elliptical orbit, this “comet” would only have been an insignificant and totally unnoticed asteroid), if only from the local but intense heat being created if there are discharge currents impinging on the comet’s surface in close proximity to it….
“…I propose that the overall low density of P67 precludes the solid aggregation of these higher density components to form “rock” or solid ice. ”
Taking your proposal into my hat. As a conjunct. Nowadays there are lots of ‘solid’ formations.
So, here we have a ‘Bob sponge’ with ‘solid’ incrustations 🙂
Thanks THOMAS for your comments. You are right that the sheer power of the discharge from the comet could be a serious problem for both the lander and the orbiter. Also the lander would be sitting there bristling with electrons and would be very attractive to the protons from the Sun, much like a lightning conductor. Who knows what effect that could have but it would not be good.
I have myself been extremely pessimistic about Philae’s chances of survival on the surface of an active comet nucleus (if it ever gets there and lands on its feet) ever since I first heard about this mission. The images being sent back by Rosetta fully confirm my fears, for the reasons connected with electric discharge which we have discussed.
Sorry to be such a kill-joy, but we’re getting into money time and the stakes are high for the two main competing models. Positions and predictions need to be stated.
Solid sublimates are, by far, the main component of 67P.
(Taking out ‘solid’, changing for de-sublimated) 🙂
It’s like ‘freeze fractioning’ a semi frozen soda: the sugar and color leaves by the straw, and the rest is an icy ‘sponge’
Hi Jacob. Freeze fraction presuppose liquid origin. As you, I believe they are present. Really interesting this idea. Adding to my hat 🙂
…Still believe that regular, cold processes are more related to innumerable cycles of sublimation/deposition inter-playing with little amounts of heavier molecules and ions.
“…The expression ‘electrical discharge machining’ often stated here distracts (me) from the fact that electrostatics play a role.”
Fully agree.
To many ‘small’ -and some not so small- clues of liquid phase. But need not to distract from the facts brought by energy budgets.
(The big big energy budget issue is: How much of it 67P catches by traversing Sun/Jupiter fields?)
Errata: [Should Be] De-sublimated gases are by far, the main component of 67P.
@ Alembe. The low densities you quote are for powders. For a given mass of powder a large percentage of the volume of that mass is taken up by air between the solid grains. The density of the solid part of the powder is greater than 1. The proposal is that the comet is made of icy material that is porous, it contains spaces between the solid materials it is made of. These spaces could be filled with the vacuum of space or gases trapped during the formation of the comet.
Hi Robin. Maybe I am wrong. Alembe is proposing both porosity and ‘honey-combing’ / ‘layer-combing’ as a general rule for 67P.
To me, the ‘wildness’ of Alembe is in his postulation of 67P as an extremely ‘breathing’ astronomical object.
How do you explain “an extremely ‘breathing’ astronomical object” in the classic model?
Alembe, because the measured density of the comet is similar to that of dusty materials on Earth you have concluded that despite looking like solid igneous rock it must be low density dusty material holding together somehow (in which case the lander would just drop right through it). Would it not be at least as reasonable to conclude that earthbound densities are not valid 600 million km out in heliospheric space and therefore apparent density (or apparent mass) is not a useful indicator of composition. We should be open minded about this with such a mission as Rosetta which has the aim of revealing to us things we do not know.
It is a pity that our winter semester is running, and
I have to prepare and give courses instead of
meditating about the news of the Rosetta mission.
Good luck for the next two weeks!
Ingo.
We’re slowly getting there (from an EU perspective), as the pictures being gradually provided show more and more detail….
After the successive shocks and surprises that the standard theory has suffered ever since Rosetta’s arrival at the comet (1/ its shape, 2/ its evident cliffs, rocky outcrops, craters and chasms, 3/ its overall charcoal-black aspect 4/ its total absence of surface ice, 5/its “layered” rock formations that can be seen in every image,7/ its jagged rocky upthrusts seen on every skyline, 8/ its hundreds of thousands of boulders lying piled up at the bases of cliff-faces), this is perhaps the BIGGEST ONE YET:
The big boulders we are starting to be shown in close-up are THEMSELVES stratified (or “layered”, if you prefer), including even the henceforth emblematic Cheops…! Emily hints at the “layered structure” of the “two boulders just below the centre of the mosaic”. It will presumably have escaped no-one’s attention, however, that the larger, even more massive, boulders above the centre of the mosaic (including Cheops itself) are actually even more obviously stratified…. The orientation of the stratified layers is even the same, in most cases, as that of the surrounding bedrock.
It’s all about pattern recognition (the very basis, and inescapable first stage, of the scientific method).
Still any takers for stratified ice or stratified dust (or a combination of either or both) in support of the standard theory? Personally, I’ve never seen a picture (or even heard about the mere concept) of either…
As surely as the west coast of Africa and the east coast of South America match because they were once one and connected; so too the “Coast” of the head of the comet and that of the body have aligned corresponding features!
Surely this means that this is neither a contact binary, nor has the neck been “eroded” away, by sublimation or electrical processes. The two lobes have moved apart like two continents adrift on their plates yet still solidly attached to each other by the neck!
No EU nor Whipple theory can explain nor predict those alignments. To work out a new theory needs more data.
What structures are inside the comet?
What makes the comet pliable enough to form into complex shapes, yet strong enough to hold that shape there?
What makes the surface so black, yet the emissions not black at all?
Hi Marco. I am asking the same question. A close encounter with Jupiter is “good maybe” in my view, but requires a lot of very special circumstances that might happen only once to a few bodies. The evidence from other bodies, a large percentage of the sample size, is that this pinched waist effect is a fairly normal occurrence. Like you I think the nature of the comet interior and the internal forces within the comet are the cause of the appearance of 67P and the other peanut shaped bodies.
There are an increasing number of double body asteroids being found, which rotate around a common centre of gravity. A similar process involving denser materials might lead to the separation of the two bodies completely. The evidence from the makeup of Itokawa found by Japan’s Hayabusa craft, shows how this is actually happening. The lose conglomerate is being separated by the object’s spin and the middle third is largely devoid of solid material. The result a pronounced dent 2/3 of the way along the body. Significantly, very similar to what we see for 67P.
Marco, it has already been demonstrated in laboratory experiments striking electric arcs onto sand that two lobed solidified shapes like that of 67P can be formed. No ad hoc explanation or new understanding is needed. Similar shapes have also been seen in other comets and asteroids.
@john We are not at the stage where we cannot imagine how a bi-lobe shape is preferentially formed by a number of possible experiments, including the one you mention. We are, without prejudice looking for clues in the form as pieces of the puzzle, to work out the history of the shape of the comet over time, and how parts that are now separate, could have been connected.
@Marco : “…and how parts that are now separate, could have been connected”.
Sorry, I must have missed something. Unless my eyes are deceiving me, the two “lobes” are still firmly joined by the neck region.
In actual fact, what started out as an elongated lump of rock is simply being electrically machined into the approximate hour-glass shape which is characteristic of too many totally disparate heavenly bodies for this to be a simple coincidence:
– example of a famous and very nearby star, Eta Carina (statistically, there are likely to be tens of billions of other stars with the same hour-glass shape in our cozy home galaxy…): https://en.wikipedia.org/wiki/Eta_Carinae#mediaviewer/File:EtaCarinae.jpg
– example of the most famous, extremely nearby “supernova” (SN 1987A in the Large Magellanic Cloud) of the past 27 years: https://images.nationalgeographic.com/wpf/media-live/photos/000/242/cache/space105-stellar-explosion_24266_600x450.jpg
– 5 examples of “planetary nebulas” (there are far too many of them to cite more than 5: you can see hundreds more for yourself by searching for “hour-glass planetary nebula” ):
https://www.spacetelescope.org/images/opo9607a/
https://phys.org/news/2013-09-bizarre-alignment-planetary-nebulae.html
https://www.slate.com/blogs/bad_astronomy/2013/09/05/planetary_nebulae_weird_alignment_hints_at_ancient_magnetism.html
https://en.wikipedia.org/wiki/Bipolar_nebula#mediaviewer/File:Planetary_Nebula_M2-9.jpg
https://www.spacetelescope.org/images/heic0910h/
– And, to top it all, even an hour-glass-shaped galaxy! It so happens to be our very own Milky Way…:
https://www.universetoday.com/78050/78050/
That’s how electricity, as a bipolar force, works by definition… It’s all about pattern recognition (just look at the pictures, ignore the commentaries and trust your eyes…), with no need whatever for the black fairy dust of the “dark matter”, “dark energy”, “dark flow” or “black holes” which are required to pull a black mask over the glaring failures of standard theory to explain what is becoming increasingly and luminously obvious.
Marco, the one I refer to has been demonstrated. You said no EU theory can explain…… The one you suggest has never been demonstrated. That does not mean it should be dismissed. It is just a matter of probability.
@Thomas. “Sorry, I must have missed something. Unless my eyes are deceiving me, the two “lobes” are still firmly joined by the neck region.
In actual fact, what started out as an elongated lump of rock is simply being electrically machined into the approximate hour-glass shape.”
Yes you have missed something. Looking at the detail of the comet shape, and the relationship between parts of the comet that are attached to the head, and parts that are attached to the body (separate parts that I was talking about) we can get an idea about whether it started out elongated then shaped, or started potato shaped then pulled apart.
If part of the head lower “coastline” fits like a jigsaw to a corresponding body upper “coastline” admittedly difficult to demonstrate with the random navcam image perspectives, then the latter is way more likely than the former.
Sorry, Marco, I don’t believe in the magical mechanisms you’re conjuring up, particularly if you are seriously suggesting that the same mechanism is at work here on 67P/C-G as that which hypothetically separated Africa and South America.
I’m the first to advocate pattern recognition as the very basis of correct scientific method, but this one is clearly a non starter.
Did you have a look at all those extraordinary hour-glass shapes I linked to above, by the way? Now THAT is what I call pattern recognition and that is what I call compelling evidence in support of a totally coherent EU theory. Comet 67P/C-G is being shaped in the same way by the same electric force.
@Thomas No magical mechanisms are required. In fact I am not even suggesting a mechanism at all! I abhor the idea of committing to a mechanism until we have a timeframe of how long things take to shape and form on a comet. First establish whether lobes are moving apart slowly, then extrapolate to the past assuming a gradual process and see if it makes sense.
We know comets have a habit of splitting up into separate viable comets. This might be a gradual process with such separating lobes.
@marco, hour-glasses are hourglass shaped too, want to know why? Ask EU (bet it has to do with intergalactic welding)
@Marco : “No magical mechanisms are required. In fact I am not even suggesting a mechanism at all! I abhor the idea of committing to a mechanism until we have a timeframe of how long things take to shape and form on a comet.”
Thanks for clarifying things.
The EU model has the huge advantage of being able to propose a precise mechanism which is currently being confirmed by the images Rosetta is sending back.
@Thomas The mechanism of EU is not “precise” by any definition of the term. There is not a single measurable quantity that EU can put into a formula and calculate. Pattern recognition is all well and good as a first point of call, but it doesn’t prove a common mechanism.
Proposing ‘electric corrosion’ 😉
As in the sea ships.
A lobe is the ship’s iron, the other one is the ‘sea’.
By the way. Why Earth is one hemisphere land, an the other sea?
OK, this is a bit too wild, but think that most of the ceramics is decanted at the ‘super-structures’, Great Wall and things like that. Currents could traverse by. The lighter, smaller structures are mainly ‘black’ ices, ‘stealth’ ices.
Vents, we have not seen them attached to the jets?
Maybe they are just not there! maybe there are two possibilities for this
1 There is sublimation taking place at the surface, and so the whole surface is active. For this to happen we need there to be water ice on the surface.( No Evidence)
2 The surface is being scared by electrical processes, the Boris dust partical measured recently is a silicate. These will break down to water and other volatiles plus more when subjected to electrical erosion. (REf Nasa experiments in the lab in the early 70’s).
Maybe if we accept the comet is in a harsh electrical enviroment, then the absence of vents is not so hard to accept.
We can see jets but no vents, in some pictures we see jets and we see the ground beneath them, but no vents
So why dont we accept that the main form of erosion at the moment is electrical? In the absence of ice at the surface, i struggle to look at it any differently.
If the Comet gets hotter and the proposed location of the ice under the surface reacts then some vents may occurr, So what?, so there are two methods contributing to the tail.
However the surface errosion is clearly the main process at the moment we have some great pictuires around the neck to support that and that means electrical.
If the potential to the comet increases and some large birkland currents become obvious as the comet gets closer to the sun, then the electrical erosion will be all the more obvious. We will see touch down and erosion of craters.
But right now the evidence is that the surface is silicate rocks (dust specimen) and that is being eroded electrically, hence the jets without vents.
If there is water there it does not make much difference that can be eroded by electrical means as well.
I can not see sublimation anywhere, if ice was measured to be on the surface, it is such an important plank in the std model, it would of made head line news by now (that comets seeded the earths oceans has already been in some papers even though our experience of a handful of Comets suggests there is no water)
Oh gooooooooood. A bit of sand for me to play with. All I need now is the water…’spose that’ll come later when it gets a bit toasty warm around dear old Sol. Keep up the good ESA…fascinating!
Well Pete, amazing what has been done with some sanded glasses in the past.
A big pack of frozzen spinach with sand ?
😉
First photos of H. NAVCAM with their natural ‘extreme’ contrast trick me into thinking of a pile of algae over the beach.
Thomas and Marco
For more evidence there are several places on the comet where rocks with an hour glass shape, although one end bigger than the other, are just sitting upright in the middle of the plains and craters.
It is as if, what ever made the comet shape has also fasioned similar shaped rocks on the comet surface. That does not appear weird if the same proces was used to fashion the comet and some of the stranded rocks on the plains of the comet
Hour glass shapes, like face shapes, don’t prove anything about a mechanism. I see a lot of interesting shapes on the comet.
I see the hourglass shape as a transition point before something becomes two spherical shapes, completely independant of mechanism.