Single- frame OSIRIS narrow-angle camera image taken on 10 December 2015, when Rosetta was 103.3 km from the nucleus of Comet 67P/Churyumov–Gerasimenko. The scale is 1.87 m/pixel.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Rosetta’s OSIRIS camera team has launched a new website to showcase their recent images of Comet 67P/Churyumov–Gerasimenko.
The high-resolution images, taken either with the narrow- or wide-angle scientific imaging camera, will show the comet as recently as the day before.
They will be posted to a dedicated website but followers can also subscribe to a mailing list to receive the images directly via email.
The cadence of the images released will depend on the scientific operations of the spacecraft and in particular on the as-run OSIRIS observations on any given day, along with the availability of images downloaded from the spacecraft.
A minimum of an image per week should be expected, up to an image a day if they are taken daily.
“Following perihelion and a far excursion, we are now back at closer distances – about 100 km – to the comet, providing a view similar to that when we first arrived on 6 August 2014,” says Holger Sierks, principal investigator for the camera at the Max Planck Institute for Solar System Research in Göttingen, Germany.
“We’d like to share this view with the community and the general public, in near-real time, as we re-approach and eventually descend to the surface of the comet.”
The images will be released by a robotic system in JPG format, raw or calibrated as available, following a brief pre-selection by OSIRIS scientists. Basic ‘metadata’ stating the date, time, distance to the comet and the Sun, and the resolution of the image will be included with each.
There will not be a detailed scientific description of the images because the goal is to provide up-to-date ‘postcards’ of the comet. Traditional image releases with scientific interpretation will still be made, separately, in the usual way.
The images will also be added to our ESA galleries and shared on our Rosetta social media channels. In addition, we plan to showcase them in a weekly blog post alongside our regular navigation camera NavCam CometWatch feature.
“This new initiative is a welcome addition to our long-established NavCam ‘CometWatch’ releases, and gives us another way to enjoy riding along with Rosetta as it follows the comet through the Solar System,” notes Patrick Martin, ESA’s Rosetta mission manager.
“Now that we’re closer to the comet again we’re looking forward to seeing its surface in more detail. We’re also looking forward to sharing a fantastic view as Rosetta descends to the surface of the comet next September,” says Matt Taylor, ESA’s Rosetta project scientist.
Subscribe to the mailing list by emailing your request to: osiris-pi@mps.mpg.de
Visit the website at: https://planetgate.mps.mpg.de:8114/Image_of_the_Day/public/
The OSIRIS dataset from both the wide- and narrow-angle cameras covering the period 20 June 2014 – 16 September 2014 are currently in processing and are foreseen for release via the Archive Image Browser and the Planetary Science Archive early next week.
Discussion: 56 comments
🙂 🙂 🙂 !
I second that, Gerald!
Am I the only one to get a warning message — “This Connection is Untrusted” — when trying to access the new OSIRIS website? (FF 42.0 on Win7)
No Erwin. Some pending issues with update of the certificate. Hoping Web Team at mpg.de help us at this issue.
OK, thanks!
Erwin: On security issues, don’t know how Trust by Certification works.
Taking an eagle view of my web browser, and it does not update the list. [push or pull model?].
Not one of my options, but if you update your browser, then your list of certificates should be, also 🙂
Certificates are handled by Windows Update as ‘Optional’.
On the floor…
OSIRIS comes through! What fun!!
Here are the south pole head-body matching shear lines.
https://scute1133site.wordpress.com/2015/12/11/67pchuryumov-gerasimenko-a-single-body-thats-been-stretched-part-30/
Hi Cooper. Where the material below the red dotted line at upper, small lobe, could come from? Do you have one, or several scenarios for this?
Have seen the same for North side, and is quite easy fitting. Is this South side estimation preliminary?
Logan
The area below the red line on the head looks quite flat and one might think how could you press the head back down onto the body with all that material sitting underneath it? It looks as though you’d press the head down so far and the curved features at the bottom would just bump against the body, stopping it from going any lower. If that happened, the red line on the head would remain about a kilometre from the body line- not the best of matches.
However, that area below the red head line consists of ridden-up onion layers. They’re well lit, so it looks quite flat but they do step back somewhat as they step down towards the conventional head rim that causes the shadow. The most obvious ridden-up layer is the red line layer itself. It shows a sharp rebate from halfway along, at the curve, and also at the V-shaped end. So the rebate on the red line is the torn end of an onion layer stratum and it constitutes a step back to the next exposed stratum as you follow it back to the cliff face it’s overhanging.
That onion layer is angled sharply upwards behind the one above it. These aren’t simple, flat strata like a neat pile of books on a table, seen end-on. They’re all angled into the core of the head at something like our line of sight towards them. So what we’re seeing is a sliced onion. This is what Marco had fully worked out back in December 2014 (for the north side) before I was led off in the wrong direction by the AGU14 ‘flat strata’ presentation and poured cold water on onion layers. That meant four months of head scratching before we resumed with them, regardless, as the only physically possible solution.
Below that main rebate followed by the red line, you can see three additional distinct onion layers mirroring the kink to the left, one deep but a bit messed-up and two ‘below’ that (in upright duck mode) which are shallower but with well-defined steps. The bottom one, just above the conventional head rim, i.e. just above the main shadow and towards the left, is so curved it’s like a river meander. Then it turns sharply right and forms the main curve across the bottom. All these layers can be traced across the whole face, with some merging and diverging but they are there. You can even see the holes in the middle of the red line curve duplicated halfway down. You have to look hard but when you see them you can’t miss them.
So all these layers, it has to be remembered, are like wooden shingles on the side of a building. The lower ones slide up almost vertically behind the ones above so the above ones are outer comet layers and the lower ones including the rim making the shadow are inner, deeper layers. All the layers above the shadowed rim, including the one forming the red line were (in my view) originally nested together at the shadowed rim and joined to the red line on the body. They constituted a preliminary shearing of the crust and rode up during stretch before the main head shearing (according stretch theory). Then the main shear happened and the whole head lobe went up. Their aggregate thickness when nested should be the same as that cliff you see at the body lobe shear line. That’s the lower red line. It looks about the right depth to me.
You can also see how, when nested together on the body, the head onion layers would be angled slightly more horizontally (in upright duck mode) than they are now. That’s consistent with all our evidence for head lobe herniation being the reason for the body onion layers being out of alignment with the head onion layers. It’s a natural artefact of any such herniation-to-stretching scenario, just like a lava lamp plume rising from a hemispherical lump at the base of the lamp.
So the answer to your question is that the area below the red line on the head was nested together and tucked right up under the layer defined by that red line. Once nested, their now much smaller area constituted the same curved shape as the one you see on the body between the red line and the curved ridge behind it towards the neck. Once you match the five holes in the middle of the head curve to their twins at the base of that cliff on the body (one of several mini matches) you have a slide direction so you can ‘play the movie’ backwards and watch everything nest down. And that bottom arc on the head then fits into that light coloured arced area in the middle on the body. That’s because it was the bottom nested layer so it has to fit there. You can even almost match the little curved ridges that define the head curve to the little ridges at the back of the light area.
And the answer to your “is it preliminary?” regarding the fit, I don’t think so, really. I’m sure I’ll see more mini matches etc and refine it but it’s pretty well there. But the next question is how did the sliced-away layers above the red line fit to the body. Both head and body were well roughed up on this side and so this shear line is effectively sitting inside the original comet shape (according to stretch theory).
So now I’ve given the game away. I don’t think all these onion layers round the head lobe rode up just a little bit. I think they rode up massively before the head sheared. There’s lots of evidence for this on the north side too.
“…ridden-up onion layers.” Thus, a lot more material ‘ridden-up’ at South Pole, than at North.
That ridden-up material is very co-planar to Body South Side.
Wouldn’t that ‘ridding’ event leave an enormous hole at Body South Side?
This is positive review: I can see the depression leaved by North rising. Slightly filled.
But the depression leaved by South rising would be enormous. Where this South Ridden-UP Material, plus Neck Material, plus actual Body Material, came from?
Are you saying that all of this [pull or push] happened when Big Lobe was a Full Size planetoid? If this is the scenario then we have there all the necessary material.
“…So now I’ve given the game away.”. Hunting allusion?
Marco, taking nothing from this. Reclaiming no authorship, at all. Just enjoying the saga 🙂
Marco: If going to keep idea of Small Lobe rising from Big Lobe, Then should start by stating that there SHOULD NOT BE matching lines at South Pole.
Ducky is missing material at South Face, The missing material is where you should be searching for those matching lines.
Hatmehit is incomplete, as a clue 😉
Logan
You said:
“Marco: If going to keep idea of Small Lobe rising from Big Lobe, Then should start by stating that there SHOULD NOT BE matching lines at South Pole.
Ducky is missing material at South Face, The missing material is where you should be searching for those matching lines.
Hatmehit is incomplete, as a clue.”
I’m glad you agree there’s missing material at the south pole. And you’d be right that it means there are matches flying around in the wake of 67P. Those layers from head and body sat as onion layers over the top of the entire vista we see in this south pole photo and when it was all closed together as a single body (all this, according to stretch theory, not mainstream). That would mean those upper onion layers sheared away along with their matches and departed for good.
But there was a point that was deep enough into the comet for the onion layers to stretch, shear and separate but not escape. In fact, in purely dynamical terms, it’s almost a given: layers at high radius values from the rotation axis went into negative g at around 0.5m/sec tangential speed and escaped at around 0.8m/sec. The material they left behind at lower layers and doing less than 0.5m/sec remained in positive g, stuck to the single body. Those radii that translated to speeds between 0.5 and 0.8m/sec were potential layers to go into orbit but not escape. Given a high rotation rate it’s to be expected that slabs will fly off the extremities and this has been documented for other comets. It’s hardly a stretch of the imagination to suggest that the model in its entirety involves ejected slabs at the extremities, and a large slab or lobe below that trying to split and escape but failing due to having a tangential speed between 0.5 and 0.8 m/sec.
This isn’t a finely tuned just-so scenario. As the supposed single body comet spins up to a 2-hour rotation rate, all these radii are spinning at or near these rates. Only tensile resistance (matrix cohesion) is holding down those soon-to-be slabs that are in negative g. You just need to push the rotation rate over a certain rate (via asymmetrical outgassing) around the two-hour value for all the above to unfold. It’s true that the actual rotation rate for failure depends on cohesive resistance but the estimated cohesion for 67P is 20-40 pascals. My estimate for the tensile force per unit area (yanking away force) at the shear plane of the head lobe at a two-hour rotation rate is 273 pascals. Calculations for the spin rates escape and orbital velocities are in this comment:
https://blogs.esa.int/rosetta/2015/09/28/how-rosettas-comet-got-its-shape/#comment-553840
And this comment for the head lobe shear plane (last four paragraphs):
https://blogs.esa.int/rosetta/2015/09/28/how-rosettas-comet-got-its-shape/#comment-559747
So 273 pa is enough force per unit area to shear the head lobe away but the acceleration that brings about that force isn’t enough to allow the head to escape (because it’s centre of gravity was at a tangential speed within the orbital speed envelope of 0.5-0.8 m/sec). Hence it went into orbit while the slabs above it at a higher radius and tangential speed escaped.
This means that all the mass loss and lost matches at the south pole that you cite does apply but all that means is that a central kernel is revealed, ready to split at orbital speed. The low tensile resistance of the neck attenuated the head lobe that otherwise would’ve orbited a bit higher.
Suborbital detritus landed down the rotation plane hence the strangely marooned boulders on Imhotep, Site A and Aker. Detritus that went into a proper orbit would’ve been scrubbed from that orbit by fairly close approaches to Jupiter such as the 7.5 million km pass in 1959 (essentially a Roche pass with a super-rarified body).
The head and body lobes we see today are the split kernel and the shear line dotted red that I linked is the shear line for that kernel. That shear line occurred and remains visible today regardless of the slabs above it that sheared away forever (again, this is all according to stretch theory and not mainstream).
Logan
As for the hole that the ridden-up lump should have left, it’s the same at Anuket. The neck doesn’t look as if it fits back in. But the matches are there, in a continuous line from Ma’at to the sharp turn at the south pole (and that line meets with the point at which my s pole red line starts, by the way).
So it behoves us to look for an explanation as to how the neck expanded, not turn a blind eye to the matches because models don’t fit a stretchy, expanding neck. The obvious answer is that it expanded like spray foam insulation with all the gases trying to escape through it and Marco’s BLEVE’s leveraging that process. It explains the ‘dry mix concrete’ surface of Anuket.
Oh, and a Merry Christmas to you Logan! I was going to send over a special Captcha bulk operations exemption gift voucher so you could free up a few hours of your day 🙂 But then I realised, all that photo matching is good practice and you might eventually slide off the fence to join us in the stretch camp.
“…The head and body lobes we see today are the split kernel” [of a former, much bigger core…]
Dominant layering at small lobe seems unbroken when crossing your red, dotted line.
Then -at your argumentation- material over the red, dotted line at big lobe should be ‘filling’ material.
Please Cooper, correct this lines if wrong.
Hi A.Cooper,
I don’t see your indicated “shear line” compatible with the sedimentology (layering).
The first 9 dots of the upper dot sequence may follow a cross-sected sedimrntary layer. In my eyes (the cross section of) this layer then continues almost straight to the right, hidden a bit under debris.
Similar (cross sections of) possible strata more distinctly exposed further to the top of the image.
I wonder, whether those might be interpretable as onion layer around the large lobe, and whether this might question the binary interpretation, and might support the erosion approach instead.
I know very well, that just looking at one image can easily be spurious. Therefore I’m far from claiming anything, just sharing my pondering.
The other interesting structures are those almost concentrically looking fracture systems; those systems appear to overlap, such that an interpretaition as layering appears inconsistent.
– You folllowed one of these circular features in the middle of your upper row of dots. –
Other approaches might be results of thermal stress or impact-related features.
My somewhat subjective impression is, that the lower concentrical system is slightly displaced at the fractures of the upper system. This would indicate the lower system being older than the upper one.
The circularity and a possible temporal sequence might hint towards impacts as the root cause of these structures.
Just saw Logan thinking in a related way.
I’ve been presuming centers of circular structures near (1230; 806) and (1171; 1057), the latter eroded away, such that only about the upper quarter still present.
Other, smaller, circular concentrical feature around (1800; 933), probably the same as Logan’s https://blogs.esa.int/rosetta/2015/12/11/ride-along-with-rosetta-through-the-eyes-of-osiris/#comment-594389
Coordinates with left upper corner as (0; 0) in image
https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/12/comet_on_10_december_2015_from_osiris_narrow-angle_camera/15729183-1-eng-GB/Comet_on_10_December_2015_from_OSIRIS_narrow-angle_camera.jpg
Hi Gerald,
Almost to the day last year, I first mentioned concentric or onion ring layers as the explanation for some of the flat areas on 67P. It just happened to be on my own blog as the first time stamped comment copied below.
https://marcoparigi.blogspot.com.au/2014/12/rosetta-note-2.html
As far as the flatness of the site A “strata”, it belies a sense of order when a lot of the comet gives the impression of haphazard disorder. Stratifications are a bit of a stalking horse for EU theories saying it is “rock”, that is planetary origin. I perceive, however, that the layers are somewhat concentric to the original spheroid shape, like onion rings. Thus, however strange it seems, they must be deposited from activity of the comet itself some time in the past. Additionally, the outermost layer (near the shear lines, for instance) has stayed static at least since the time stretch occured. Most near surface sublimation models have the outer surface ablating or collapsing from mass loss inherent in cometary activity, which would destroy most evidence of stretch. Clearly, the models have this wrong, I think the flatness is related to the process of internal stratification.
22/12/14 22:29
Marco
And it wasn’t a passing thought. It was fleshed out and I then joined in with some supporting info even though I wasn’t totally convinced at that time.
A Merry Christmas to you, by the way. I was going to send over Heston’s latest centrifugal onion slicer but it seems you worked out how to do that a year ago 🙂
Thank you.. I think. Merry Christmas to you. Apparently, if it isn’t in peer reviewed papers, it didn’t happen.
It’s hard to make headway with scientific “in reach” with a blog primarily designed for “out reach”, but I am still grateful for the conversations, and look forward to new ones next year.
Gerald
I should just start by saying I don’t expect the shear line to follow strata lines at all times. It doesn’t do so on the other side of the head either. It might be a preferred line of least resistance but it depends on the direction of the stretching/tearing force (if one subscribes to stretch theory) and any collateral tipping and balancing adjustments that could momentarily cause compressive forces to hold sway.
That curving-up extension after the first nine red dots on the head does look like a fracture plane from this view. However, it’s in fact a tear through all the fracture planes that run across the flatter, central area. The tear (or lots of erosion if you’re thinking of erosion theory) left a ragged area which is the area beyond the tear from this viewpoint. You noticed strata in that area. Those strata belong to the strata that were formerly part of the flatter face before the tear. They are the flakey remnants that had been buried deeper inside the head.
The following picture shows this area from ‘above’ and it can be seen that the ragged strata are indeed a continuation of the flat area strata. Since these are onion layers curving round the head, whatever you see as end-on is deceptive. All end-on strata on the flat area are angled upwards and slightly leftwards (in upright duck mode) into the flat face. This means that the nature of the torn section beyond your curving line is that the tops (and messy sides) of these strata are being exposed, like slicing a piece of puff pastry at a very acute angle. You can look down onto the top suface of each puff pastry layer. On the other side of your curved tear, lower down the head, the angle of the flat face is more smooth and ‘vertical’ so it exhibits them as conventional strata. Here’s the photo looking from above:
https://scute1133site.files.wordpress.com/2015/04/img_0031.jpg
The green lines are extensions of the flat face strata. The corresponding flat face strata are dotted yellow at either end.
And here’s the same thing from yet another angle, with your curving line annotated in pink:
https://scute1133site.wordpress.com/photos-for-off-site-comments/
Your ideas relating to the curved areas lower down are, I believe, addressed in my comment to Logan, except of course, in time-honoured tradition, I have a different interpretation 🙂
Gerald
Also, I think it’s telling that the step-back of the red line onion layer is less well defined across the middle area and it corresponds exactly to the run of holes along that line. As soon as the holes stop the ridge becomes deep and angular.
Oh, and Gerald, a Merry Christmas to you! I was going to send over a nice knitted jumper but I was worried you’d say it was too woolly, just one long, long yarn tied up in thousands of knots and you simply won’t wear it…and that I couldn’t prove it was a jumper anyway since I’d neglected to supply the pattern 🙂
Working for the first time over Cooper ideas, hopeful He and Marco don’t disturb at reading slight divergences of their work.
How about this script:
a) Binary never happened. [Anyway binary has a single digit probability of unary].
b) If preferred models so eager to accept accretion, should also be willing to accept des-accretion. A two-way process, depending on formative environment timing and placing.
c) Ducky, a single object, accreted to a third, much bigger object.
d) Ducky fractured on accretion|impact, and the fracture lines at North Face are still present, as signaled by Cooper&Marco’s work.
c) South Face is simply the accretion|impact face.
d) Ducky des-accreted at a later time.
ERRATA. Should say: “to a second”
Why Ducky des-accreted as a single object?
Because Ducky was much younger -and a lot less depleted- than today.
Also because Ducky accreted|impacted a regolith covered surface. Loosely attached by South Plaque, only. The material for the ‘healing’ was already there. Ducky only contributed sintering sublimates.
[Ices below regolith could have contributed, also].
And Not. No substantial Ices below regolith [would not behave as such]. Asteroidal kind object. Re-word: South Plaque should be crushed material of both, hard sintered by Ducky’s sublimates, also.
Even this improbable script [asteroidal material a lot less common than cometary kind] brings new paths of though:
“…Loosely attached by…a plaque”. A ‘big’ asteroid is not an efficient gravitational accretive object. Asteroids accrete slowly.
As VDW forces are determinant for grain grow|assembling|deposition, Sinter-ing is determinant for cometary accretion .
To grow fast -and big- cometary material core[s] plausibly needed.
This is fiction.
Hi Logan,
Accretion is just not something that is evident on visited comets. It is an assumed primordial process with no causal evidence chain. Thus, the opposite process is a little meaningless to me.
The proximal cause for all the morphology is extremely constrained by the evidence that it has left behind. The layers and the matches say it all. The matches mean that it broke apart and the fact that they still match constrains erosion to be of the type that doesn’t erase matches.
The layers, like on Earth tell us what has happened, because by Steno’s law they were originally concentric to a spheroid shape, and, the folding, shearing and sliding can be traced back to show the most recent movements. It’s not rocket science but pretty much Geology. AGU15 should be all over it, but they are stuck with pristine accretion paradigms…
“… the fact that they still match constrains erosion to be of the type that doesn’t erase matches”.
[recent? erosion]
Another parabolic segment with focus at pixel 1329,723. So many ‘impact cones’?
Full resolution 2048px version of:
https://blogs.esa.int/rosetta/2015/12/11/ride-along-with-rosetta-through-the-eyes-of-osiris/
https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/12/comet_on_10_december_2015_from_osiris_narrow-angle_camera/15729183-1-eng-GB/Comet_on_10_December_2015_from_OSIRIS_narrow-angle_camera.jpg
Many circular features I formerly identified as ‘gently accreted, medium size comet-esimals’ could also fit in an erosive, axial cut of ‘impact cones’ scenario. Revising my own ideas 🙂
Due to intersection of some circular structures, I’m with you, Logan.
Appear radial from Hatmehit.
‘Stirrings’ at South small lobe, with sources at layers located at pixels:
1477,484
1397,553
1408,614
Full resolution 2048px version of:
https://blogs.esa.int/rosetta/2015/12/11/ride-along-with-rosetta-through-the-eyes-of-osiris/
Central enervation at Hatmehit seems to be -somehow- related to ‘concentric’ feature at pixel 1798,949.
An impact contributing additional sublimates?
And of course, cometary [depleting] material seen in cross section, looking like hieroglyphs. Beautifully simple, in its complexity…
It took me a while to get used to the detail. The view is similar to Cometwatch 17 November. On the right the smaller lobe with Hatmehit on the right and Wosret on the left, on the neck Sobek, and on the bigger lobe Anhur to the right and Khonsu to the left.
I am very very confuse !
After a blackout of 18 months about OSIRIS pictures,
even if a large number of people asked fot them,
now Prof. Sierks promises OSIRIS picture in real time!
It is impossible to understand why in the past NOT
and now YES.
Lahar activity at the body side of the neck?
Pixels
704-1422
694-1214
320-1303
589-1466
Full resolution 2048px version of:
https://blogs.esa.int/rosetta/2015/12/11/ride-along-with-rosetta-through-the-eyes-of-osiris/
This porosity also should be refereed speleologically.
ERRATA: Should say referred.
endlich! danke!
Many zones does not present any particularly dominant layering, thus giving a visual allegory of archaeological items of basketry.
I get (in USA):
https://planetgate.mps.mpg.de:8114/Image_of_the_Day/public/
The URL is not valid and cannot be loaded
Mineral crystallization dominant, but interacting with organics.
Any, even the most imaginative space movie, has not prepared the world, for this.
Space exploration has a before and after, Rosetta.
Got it, plausibly related, Kamal 😉
A question I was curious about was whether a smooth Hapi-like region continued all the way around the neck on the bigger lobe. That is not the case here in the southern hemisphere although there seem to be plenty of boulders strewn all over the place. Why? Is a prolonged exposure to the Sun required for the smooth regions to form?
As one moves left of the central “valley” full of boulders on the big lobe there is a large “cave” (overhang is a more modest word) with a parabolic shaped roof. In the second Osiris picture (12 December), if you undazzle the white areas, you can find this cave and one can see plenty of action happening inside.
More than curious, was my expectation. Reality will always surprise me.
Processes at play are going to bring ‘Dantesque’ views 🙂
Re the third Osiris picture (16 December): We have already seen an animation of this kind in https://www.esa.int/spaceinimages/Images/2015/08/Comet_s_dusty_environment from 13 August. Cannot say this image adds much content compared to that. To be frank I do not know how I would distinguish this scene from the earlier one of 13 August.