Ceres High Altitude Mapping Orbit (HAMO), Late summer through fall 2015 Options

[Holder of the Tw...]

DAWN arrived in its new lower mapping orbit on August 13th. The DAWN team is preparing to resume science observation tomorrow on the 17th.

From the Current Mission Status page at the DAWN website:

August 13, 2015 - Dawn Arrives in Third Mapping Orbit

Dawn completed the maneuvering to reach its third mapping orbit and stopped ion-thrusting this afternoon. This was a little ahead of schedule because the spiral descent went so well that some of the allocated thrusting time was not needed. Since July 14, the spacecraft has reduced its orbital altitude from 2,700 miles (4,400 kilometers) to approximately 915 miles (1,470 kilometers). The orbit period has correspondingly decreased from 3.1 days to 19 hours.

Dawn is scheduled to begin its new observations on the evening of Aug. 17 (PDT) and continue for more than two months. First, however, the mission control team will measure the actual orbit parameters accurately and transmit them to the spacecraft.

[Guest_Steve5304_*]

Cant wait to see spot 5

[Habukaz]

In the latest Dawn Journal it is mentioned that pictures and other data from HAMO have started arriving on Earth, so it shouldn't be that long now before we get a look.

Nothing at all negative about the image release policy, but I have long since got bored of seeing the same terrain with the same resolution from a slightly different angle. (HAMO and LAMO are of course more promising in this regard)

[RotoSequence]

The first three HAMO images have been released: http://www.nasa.gov/jpl/pia19631/the-lonely-mountain

[Steve G]

For a world that we expected to have slushy ice, that sure looks like a rocky surface. I was expecting a Calisto kind of look but that sure looks like the Lunar surface to my untrained eye.

[FOV]

Cropped Ceres mountain image from today's release. Again the albedo variances creating a saturation/glare effect. To me it looks like the bright material could be deposited from several vents found on both the mountaintop and flanks.

[alk3997]

... To me it looks like the bright material could be deposited from several vents found on both the mountaintop and flanks.

It is interesting that within the bright streaks there does not appear to be any craters, even though outside of the immediate area there is a good small crater population.

Whatever is going-on must be a very localized event, at least on the surface.

Andy

[Habukaz]

Consistently in the three images, slopes (whether on mountains or crater walls) have few to none craters. This is presumably due to mass-wasting, relaxation or similar. I believe this is the norm on celestial bodies.

The summit itself looks like it could be cratered, but several shapes certainly look elongated.

[TheAnt]

Yes there's craters on top, and that area looks as old as the surrounding terrain that IMO gives the impression that the mountain have been created by a force from below. In short, that it is a pingu or created in one somewhat similar process.

[Charles]

If I have my compass bearings right, it's now clear that the North, West and East slopes of the mountain are not only "shiny" but craterless in contrast to the Southern slopes (partly in shadow) and plateau which appear heavily cratered. Presumably young versus old. Along the Western slope there is a circumferential discontinuity about halfway down, broken by a thick ridge that appears to have a splash of debris at the bottom. There appear to be two or three bright spots on the plateau, far from the slopes, and one partway down the cratered slope on the Eastern side.

I can't wait to read speculation on all this. What's going on?

[atomoid]

yes, its all too fascinating.. it really looks like some sort of plug thrust up pingo-style, slowly covering the surface outward as it grew, with one side becoming too steep and wasting down to erase craters and reveal underlying brighter material.
Many craters appear to have been gently lifted up along with the mountain surface (green arrows) a few of those higher up the incline appear to have been elongated by slippage.
Some landslide splashing out across the floor at the foot of the mountain (yellow arrows).
Apparent large mass-wasting event on shadowed side perhaps was too slow to disturb its surface. hard to say whether the splash smudge at the bottom post-dates that event (red arrow).

[Guest_Steve5304_*]

yes, its all too fascinating.. it really looks like some sort of plug thrust up pingo-style, slowly covering the surface outward as it grew, with one side becoming too steep and wasting down to erase craters and reveal underlying brighter material.
Many craters appear to have been gently lifted up along with the mountain surface (green arrows) a few of those higher up the incline appear to have been elongated by slippage.
Some landslide splashing out across the floor at the foot of the mountain (yellow arrows).
Apparent large mass-wasting event on shadowed side perhaps was too slow to disturb its surface. hard to say whether the splash smudge at the bottom post-dates that event (red arrow).

I see less of a indigenous mountain...more like a snowball hitting a wall. Thoughts?

[Bill Harris]

http://photojournal.jpl.nasa.gov/catalog/PIA19631

Whoa. It's the Big Rock Candy Mountain. THE most primo example of pareidolia I've seen in a while.

Subsequent HAMO and LAMO images ought to be interesting...

--Bill

[Explorer1]

Imagine the surface view on that tiny flat strip between the base of the mountain and the crater rim. A big hole right next to a enormous mound; what a bizarre little world!

[nprev]

Absolutely bizarre. Note also the large landslide of dark material on the top edge of the crater immediately adjacent to the mountain.

Haven't got a clue what's happening here.

[Yadgar]

Hi(gh)!

Is it just me or does the mountain in fact look like an exact negative of the crater, rotated by 90 degrees?

See you in Khyberspace!

Yadgar

[hendric]

If it was a pingo, how did it end up starting there instead of inside the (presumably) weaker crater floor to the south? It does look like it is at the intersection of a couple of valleys, so maybe those allowed deeper cracks to reach down, far enough away from the crater? I am not 100% on the crater being older than the mountain - the slopes on both show no craters, and interior of both don't qualitatively seem much different.

The horizontal banding on the slopes is what surprises me. Are those real layers or some kind of side effect of a talus at angle of repose? In either case, none of the nearby craters have horizontal banding, just typical vertical mass-wasting bands.

Definitely a head scratcher!

[HSchirmer]

Hi(gh)!

Is it just me or does the mountain in fact look like an exact negative of the crater, rotated by 90 degrees?

See you in Khyberspace!

Yadgar

Yes, I noticed the same thing.
The "Lonely Mountain" bears a striking resemblance to the adjacent crater.
It looks like a giant golf divot.

[antipode]

I wonder if high resolution mapping might not eventually find more of these 'things', albeit at smaller scale.

It would be very strange if there truly was only 1.

P

[Habukaz]

That, or older ones that have been eroded almost beyond recognition. I can only imagine that a direct hit on a feature like that with a sizeable impactor could do some serious damage (or destroy it completely).

[Bill Harris]

Definitely a head scratcher!

Yess!!! That is a good decriptor-- the closer we look, the odder it looks back at us. As I have noted with some of the Rosetta-features, it looks almost M.C. Escher-esque.

My preliminary take on it is that it is a "mud volcano", a deposit driven by a hydrothermal vent composed of entrained detritus and residual salts. And much akin to the Occator Spot5, and the other large spots and the many many small spots scattered about. These spots will prove to be a major feature (and enigma) of Ceres.

Note, for example, the "small' 2000-meter diameter light-toned spot about 13000 meters to the southwest (to the right on the image-view) of "Tall Mtn". It was barely noticeable on the Survey Orbit images but is somewhat prominent on the initial HAMO image and who knows about future views.

--Bill

[Habukaz]

By the way, I just realised that Gaue crater is similar in size (84 km) to Occator (90 km), so to get an idea of what Occator will look like to us shortly, take a look at the image of Gaue.

As far as I can see, we've also been promised a fresh HAMO image later today.

[HSchirmer]

Yess!!! That is a good decriptor-- the closer we look, the odder it looks back at us.

It still looks like a golf divot.
"Dantu's divot. An antipodal shock feature."
Ever seen an elliptical water-drop-basin? You let a drop of water fall at one focus, the ripples spread and reflect,
the reflections converge, and a drop of water jumps up from the other focus.

Mimas has a huge crater, and at the other side the crust is broken up by a series of cracks and chasms.
If you think back to Vesta, there is some interesting topography antipodal to the Rheasilvia impact basin and a few peer reviewed papers. Image of Vesta below.
Basically, at Vesta, the antipodal area is uplifted with a (probably) later crater at the focus and a "splat" area where craters are missing or disrupted.

At Ceres, Lonely Mountain is just about antipodal to Dantu crater. The antipodal area has valleys/faults, a crater, and the Lonely Mountain.
Situation is bizarre; looks as if a chunk of crust poped out, settled back to the surface, followed by weathering to create smooth talus slopes.

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[hendric]

Ice I surprised me at being stable to near gigapascal pressures when I checked, so I suppose it is possible that as a Cerean mantle/ocean freezed out, the pressure underground caused/causes water volcanism, or ice extrusion, or crustal tilting of large blocks like this. That's what I was just thinking, that it looks like a portion of crust has been pushed out along a couple of fracture lines.

I can buy a lack of cryovolcanic features on Ceres based on not having enough energy when the crust was thin, and now that the crust has thickened any water freezes before reaching the surface, pushing up on this block, similar to the dome at Mount St. Helens. (neat time lapse at https://www.youtube.com/watch?v=h6B1myUKAS4 ) The wrinkle is the singular rarity of this mountain - was this the weakest spot on the crust, and the pressure from beneath isn't high enough to push any where else?

With the layers visible in the slopes, I wonder if those are not typical angle-of-repose talus slopes, but slopes caused by sublimation off the original cliffs as they extruded, similar to the Grand Canyon with sunlight instead of water acting as the erosive force? With the original crust acting as a protective "cap" on the top. Except I would expect the south side (closest to the crater) to be less eroded. (scratch scratch)

Someone care to guess the volume of the Lonely Mountain? (I keep hearing dwarven singing!)

[Habukaz]

Ooo, look at that:



Something happened here. (and not very long ago)

http://photojournal.jpl.nasa.gov/catalog/PIA19635

[Habukaz]

After searching a bit, it seems almost certainly to be an area featured in Survey images 13, 24 and 25.

Seems like a regular landslide related to a crater sitting on the rim of a much larger crater:

[HSchirmer]

Ice I surprised me at being stable to near gigapascal pressures when I checked,
(snip)
That's what I was just thinking, that it looks like a portion of crust has been pushed out along a couple of fracture lines.

Yep, found the correct term = "hertzian cone". When a piece of glass is shot by a bb-gun, you get a conical hole and a conical chip.
The shiny sides make the mountain look like a conical chip that was knocked off, flipped over, and landed beside the hole.

[Herobrine]

By the way, I just realised that Gaue crater is similar in size (84 km) to Occator (90 km), so to get an idea of what Occator will look like to us shortly, take a look at the image of Gaue.

I'm looking forward to our first look at Occator from HAMO. In July, I put together this preview of what we can expect in terms of Occator size at HAMO and LAMO in Framing Camera imagery.

Note: That image is 1/4 actual resolution (each frame is shown at 256x256 instead of 1024x1024)
LAMO is going to be mind-blowing; the area of the spots will fill the entire frame.

In case it isn't obvious, the top row contains images from the second mapping orbit; the middle row contains simulated views from HAMO; the bottom row contains simulated views from LAMO.

Edit: Updated the image, adding the most recently published survey orbit image of Occator (as long as I'm reposting, I might as well update/improve it).

[Bill Harris]

Something happened here. (and not very long ago)

Yes. This relates to a very common Cerean feature, what I informally call a "flowage" or "slippage", for lack of an equivalent terrestrial analog. This has been seen in the SO images where a large (on the order of hundreds of Km) of the surface slip and flow in a fluidic manner. This occurs "internal" to craters as well as "external" to craters, and seems different than simple mass-wasting (although there are similarities).

This particular feature in HA-4 is on the order of 15-20 Km is size, which by terrestrial standards would be a continental catastrophe.

Tighten your seatbelts. This is only the fourth HAMO image...

--Bill

[Daniele_bianchin...]

Probably my eyes but resemble a cone ;-)

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[MarsInMyLifetime]

Probably my eyes but resemble a cone ;-)

If the sunlight is from the right of this picture, then there is a peak with its shadow projected to the left. And it appears to have a small crater right at its peak. There may be more to find now that we have good enough resolution for this scale of object.

Edit: But now that I found where this clip came from, I see that it sits inside a depression and the slope is more "hummocky" than "conical." Its formation may have been fairly unexceptional.

[MarsInMyLifetime]

Just a short distance to the 1:00 position of this mountain is a linear object. I took it to be a dike or scarp at first, but it almost has a platey appearance as if it were being thrust up. If this is in fact a pointy plate, the upthrust mechanism could be similar to what has lifted the regolith-covered peak of what I like calling Little Prince's volcano."

[antipode]

Well spotted! Yeah that looks suspiciously related.

I also wonder if the top of the mountain really is exactly like the clearly ancient terrain that surrounds it.
It looks different to me - although possibly its just some kind of mass wasting...

P

[Daniele_bianchin...]

If the sunlight is from the right of this picture, then there is a peak with its shadow projected to the left. And it appears to have a small crater right at its peak. There may be more to find now that we have good enough resolution for this scale of object.

Edit: But now that I found where this clip came from, I see that it sits inside a depression and the slope is more "hummocky" than "conical." Its formation may have been fairly unexceptional.

Many Thanks for your explain

[Bill Harris]

Three views, and musings, of "Tall Mountain", Ceres


Exaggerated View
https://univ.smugmug.com/Dawn-Mission/Ceres...enh4--ref-L.png

Relief and Elevation Maps
https://univ.smugmug.com/Dawn-Mission/Ceres...rt--annot-L.png

First HAMO image
https://univ.smugmug.com/Dawn-Mission/Ceres...t-N--enh1-L.png

--Bill

[Daniele_bianchin...]

often, when I see these things in the Italy seas I think at the mountain of Ceres, I'm serious...
This not a speculation, obviously Cererean Mount is a geological structure.
Daniele

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[Habukaz]

Two news articles from MPS and DLR:

http://dlr.de/dlr/en/desktopdefault.aspx/t...#/gallery/20333

"Presumably, the mountain is younger than the crater, but to determine this precisely we need to wait for the images from the next orbit and data from the spectrometer, which will hopefully determine what material is on the surface."

The craters on the dwarf planet are comparable with craters on a rocky body such as the Moon, indicating that the crust of Ceres may not be very stable. One possible explanation for the flat crater interior [of Gaue] is that molten material may once have filled the crater. “In any case, something must have happened there after the crater was formed.”

Next to a mountain chain, fine fissures can be seen, as well as more evidence of loose material on the crater rim. [...] "The unusually smooth plain [in Urvara] is most probably formed by the deposition of fine material that was presumably once molten. These are, of course, just initial suppositions that we are discussing in the mission team," adds Jaumann

http://www.mps.mpg.de/4087934/news_publica..._9379333?c=6775

The structure of the mountain top can be seen much more clearly than before. “It is actually more a type of high plateau. The surface looks strikingly similar to the surroundings at the foot of the mountain,” is how Nathues describes it.

“The bright rays [on the conical mountain] are possibly flow structures,” says Martin Hoffmann, a member of the camera team at the Max Planck Institute for Solar System Research. Investigations over the coming months should show whether they are connected to possible cryovolcanism.”

[ZLD]

Thanks for those Habukaz.

It is especially intriguing that the plateau would have a surface in similar appearance to the much lower surrounding ground, while the sides are so smooth. Even more so if it is a result of some sort of fault uplift with the lack of a large amount of distortion.

It almost seems like the surface became extremely elastic when the impact occurred. Such as the case where you push on a water bed, the nearby ground was forced upward. This would require some liquid or something very near the liquid state to be heated during impact, for this to occur however.

Here's a cropped and enlarged version of the area with a little more processing.



Something else I hadn't noticed previously is the small debris(?) pile at the bottom of the mound near the 5:00 position. Seems to be the only one like it. The linear feature that extends above it also seems to extend away from the average slope as well.

Edit: Also, here's an enlargement of the HAMO 4 image as well.


(click to enlarge)

Most interesting to note here is the... smudgyness of the features extending northward (or towards the top of the image) from the uppermost large crater. Deep fault line maybe?

[Bill Harris]

Digging out the soil mechanics and slope failure analysis reference books and hitting the 'Net for a bit of library work. Do we know of references for slope stability and/or angle of repose for low-gravity atmosphereless worlds? In the classical refs, all I can come up with for gravity is the tie-in to density, and an atmospheric/moisture effect for interparticle friction/internal friction. I'm looking for ways to analyze these "flowages" and "slumpages" that we see on Ceres. And I keep coming up with wet, liquid-y flow processes and I'm looking for alternative views.

BTW, the angle of repose for "Tall Mtn" is 2.5-3:1, which might be reasonable for a granular material in terrestrial conditions. FWIW.

--Bill

[Habukaz]

The strange feature close to a crater from Survey orbit is back, and it still looks pretty weird to me:



http://photojournal.jpl.nasa.gov/catalog/PIA19881

(just like the apparent landslide, it also features in Survey images 13, 24 and 25)

Something else I hadn't noticed previously is the small debris(?) pile at the bottom of the mound near the 5:00 position. Seems to be the only one like it. The linear feature that extends above it also seems to extend away from the average slope as well.

Nice catch, I also see it. I think there might be smaller versions of it around, though (both the ridge (it casts a shadow) above and the 'pile' itself).

[ZLD]

Here's an enlargement of HAMO 5.


(click to enlarge)

The feature definitely continues to look strange. If the white material here was just slightly under a dusting of the grey material, why aren't we seeing it where this more rectangular edge is located? As I recall from the animations I did of this spot from the survey orbit images, the crater just south of of the rayed crater, is another uplifted mound with a large crater at the top. The craters with the white flecks always seem to have very sharply definitely edges and steep walls. I'll be very interested to see Spot 1.

Here's that animation once more:

(click to animate)

[Charles]

First HAMO image
https://univ.smugmug.com/Dawn-Mission/Ceres...t-N--enh1-L.png
--Bill

Let me go out on a limb on the lonely mountain. If this is an uplifted feature, I've been puzzled by the lack of debris around the base.

Now that I'm looking more carefully, I see relatively fewer small craters around the base to the North and East (12-4 o'clock), especially between the mountain and the crater (12-2 o'clock). There is obvious flow INTO the crater (11 o'clock). And to the Northwest and West, perhaps what looks like a splash or flow (11-9 o'clock).

What if the Northeastern half of the mountain lifted first? The ice (?) interior was exposed as the regolith sloughed off. By this interpretation, the Southwestern quarter of the mountain has uplifted more recently, carrying its cratered surface with it. The regolith has not yet sloughed away. I see no sign of debris flow (yet) there, around the base of the mountain (~9-4 o'clock).

Alternatively, the lonely mountain results from a single uplift event, but for whatever reason the rake of the NE half was steeper -- causing the powdered regolith to slough away there.

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[ZLD]

Looking at the crater with the shelf, I think the strange feature could be a very large slump.



In red is a rough outline of the crater wall. If it slumped forward and down I think it could result in what we see here. In green is entirely a speculative fault line that isn't apparent in any images yet returned.

[Bill Harris]

...and why the unusual thin-and-splashy light-toned rays?

--Bill



EDIT= That is not Haulani. Look at pia19595 (SO-27)-- this unnamed "slump" crater is in the upper left edge and Haulani Crater is near the lower right edge. SO-27 is not oriented with North perfectly "up"-- it is a NNW track betw Haulani and this unnamed crater. And to further confabulate things, Haulani crater has it's own fine set of sparklies.

--Bill

[ZLD]

Whoops, wasn't sure on the name of this crater and just took a guess. Thanks for the correction.

The rays wouldn't be related to the slump necessarily. Those could be from an impact blowing them outward followed by the slumping of the side of the crater inward after a quake at a nearby fault line or just because of uneven heating of the ground.

In this higher resolution image from HAMO, it looks very similar Haulani (I think previously Spot 1?) with the pattern of white material. In previous images theres a bit of evidence in my opinion, to show that Haulani is the remnant of a caldera and the white material is from sputtering magma outward. In this 'slump' or 'shelf' crater, it could be from a similar event. Possibly a single ejection event occurred and when the magma chamber emptied, it left a cavity that was partially filled by the slumped edge.

[Bill Harris]

No problemo-- it's hard to tell who the players are. And on the "current best Ceres map" that area is near where the resolution goes from good to less-than-good and it's hard to tell. It may be some time before the maps get updated with all of the SO imagery.

I have most ("selected") of the SO images with added Feature and Annotation Overlays where I can outline the "slumpages and flowages" and Faculae (bright spots) and a couple of flavors of Lineations and plan to use the Survey images as an Index for the more detailed HAMO and LAMO imagery.

--Bill

[hendric]

The lighting is really screwing with my head. Does anyone else see the double crater in HAMO4 as a caldera, a la Olympus Mons? I get a feeling that there was a pyroclastic flow to the NW that etched the ground, giving it those lineations and making that area fuzzy.

[Bill Harris]

Yes, I have been thinking that many of these craters look quite un-impactlike. This takes us back to the early days of Lunar exploration where there was a vigorous debate on the Impact or Volcanic origin of craters.

And on the Second Day of HAMO...

--Bill

[dvandorn]

Bill, you posted that exactly as I was bringing the thread up to post the same thing. These craters may be impact-formed, but if so, the target material has far different properties from what we've seen on rocky worlds, and also far different from what we've seen on icy worlds farther out from the Sun. Some of these flows look more like they were blurped onto the surface, not thrown as ejecta or erupted as volcanic units. More like a they were vomited onto the surface.

I wonder how much difference it makes that Ceres is too close to the Sun for the exposed ices to completely resist sublimation, yet too far from the Sun for a world with so much water to be primarily rocky. We're in a different thermal environment for a watery world than we've seen before. Perhaps that's what is driving the strangeness we're seeing in the surface features.

-the other Doug

[JohnVV]

The lighting is really screwing with my head. Does anyone else see the double crater in HAMO4 as a caldera,

on that image ... No

normally if the shadows are UP or on the RIGHT the brain sees craters
if the shadow is DOWN or on the LEFT people see mounds

[Bill Harris]

For sure, Doug. This world is going to be driving planetologists bonkers for years to come. I was hesitant to stir the pot again and suggest impact or non-impact, but I kept wondering if this or that feature is a cradera or a calter.

I'm almost giddy awaiting higher rez images of the Occator Fluctae (to get in step with proper terminology)...

--Bill



ADDED: In reflection, one thing we have learnt with Comet 67P/C-G is that crater-like structures are not always caused by impact. These active pits or vents are sublimation-related features where the icy material in warmed, loses it's volatile "cementation" and erodes in a circular manner with increasing depth. An icy world like Ceres formed near the frost line would be much more prone to this than our Moon, which by virtue of it's formation process was devolatilized, or other small bodies, like Vesta, which are rocky.

--b

[TheAnt]

@MarsInMyLifetime: The "Little Prince's volcano." Cute name for the mountain. That's why I am advocating that this feature be named Saint-Exupéry, even though it seem less likely that it might be an actual volcano.

....
Now that I'm looking more carefully, I see relatively fewer small craters around the base to the North and East (12-4 o'clock), especially between the mountain and the crater (12-2 o'clock). There is obvious flow INTO the crater (11 o'clock). And to the Northwest and West, perhaps what looks like a splash or flow (11-9 o'clock).

What if the Northeastern half of the mountain lifted first? The ice (?) interior was exposed as the regolith sloughed off. By this interpretation, the Southwestern quarter of the mountain has uplifted more recently, carrying its cratered surface with it. The regolith has not yet sloughed away. I see no sign of debris flow (yet) there, around the base of the mountain (~9-4 o'clock)....

Yes I also noted that there's craters on part of the mountain slope, but not on the other sides, so yes also I wondered if it might one unusual pingu like iceplug that first tilted up on one side, and then on the other to give that appearance.
But since I am unable to even find a speculation why it should behave that way I left that idea rest here, until you now mentioned it.
So yes it's a possibility, but until someone can come up with a example of such a stepwise behaviour I will go with the idea that it is a single event that created the mountain and that we simply see crust material that happened to stick together in those positions.

.............The feature definitely continues to look strange. If the white material here was just slightly under a dusting of the grey material, why aren't we seeing it where this more rectangular edge is located? As I recall from the animations I did of this spot from the survey orbit images, the crater just south of of the rayed crater, is another uplifted mound with a large crater at the top. The craters with the white flecks always seem to have very sharply definitely edges and steep walls. I'll be very interested to see Spot 1.

I agree it is odd, unless the white material is salts, and the crack happened to contain a splinter of ice brought closer to the surface by the impact that sublimated afterwards. (This means that that crater could have more ice on adjacent sides that simply happened to have more ice that just got it lucky by being covered by more regolith / asteroid dust material - only said as one possible solution to what we're seeing here.)

[HSchirmer]

In reflection, one thing we have learnt with Comet 67P/C-G is that crater-like structures are not always caused by impact.
These active pits or vents are sublimation-related features where the icy material in warmed, loses it's volatile "cementation" and erodes in a circular manner with increasing depth.

Actually, the best analog for Ceres may be Mercury. Both have surface material near the melting/sublimation point.

Some of the Mercurian crater pits share features with Cere's odd craters,

http://messenger.jhuapl.edu/gallery/scienc...4M_RA_3_web.png

And consider the stunning images of Mercury's "hollows"
http://news.nationalgeographic.com/news/20...-space-science/

Then compare those to Habukaz's croped image of the crater-

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[Guest_Steve5304_*]

Maybe lonely mountain is an ice spike. We know ceres has liquid/slosh water below. An impactor.comes in and hits a spring and exposes it to the vacuum and low gravity of space and it freezes into this big ice mountain which is shaped so strange on its sides it has to be ice. I see lots of evidence of temporary flows on the surface and they are all adjancent to larger impactors.


https://en.m.wikipedia.org/wiki/Ice_spike

[Bill Harris]

One good reference to refresh the impact vs volcanic discussion is The Measure of the Moon, by Ralph B. Baldwin. This is one of the seminal works in planetology which shifted thought towards lunar impact processes on the 1960's and influenced views on other planets. Although Baldwin was an impact advocate, he does present both sides of the debate. It's just hard to find a volcanic crater advocate nowadays.

A review of the book of you have a Science Mag account:
http://www.sciencemag.org/content/140/3565/374.1.citation

No e-book available, but here is the Google Books page:
https://books.google.com/books/about/The_Me...id=LZMHAgAACAAJ

Ceres will prove to be a worthwhile world and will bring about some major changes in thought about impact processes.

--Bill

[dvandorn]

Yes -- Both Spudis and Wilhelms (two of my favorite lunar science authors) give kudos to Baldwin. And wasn't it Baldwin who, after holding stubbornly to other theories for a time, finally pronounced Barringer Crater an impact feature?

I completely agree, Baldwin is seminal for impact theory. And much of the later work, from many people including the above-mentioned, has expanded on the dynamics of ejecta formation and re-emplacement, shock effects on the impact targets, and development and emplacement of impact melt sheets on rocky bodies and also on hydrated rocky bodies like Earth and Mars. And on the propagation of energy into the impact target, something I think is key to the festures we're seeing on Ceres. I think a lot of the cryovolcanism we're seeing might be the result of impact-generated temporary heating and agitation of Ceres' icy mantle (or perhaps subsurface ocean/convecting warm ice mantle), causing sudden movement and eruption of subsurface materials.

It appears that there has also been ejecta splash resurfacing going on around the larger basin-forming impacts. And the large, extremely relaxed basins we see wouldn't just have relaxed like that immediately -- the impacts would have moved and displaced a lot of the material around and below the impact site, which would have pushed back in (and up) to raise the basin floors back up. That movement would affect the entire mantle in one way or another, and I bet it would cause cryovolcanic processes and features.

Of course, all of this assumes that Ceres has some kind of either liquid or convecting warm ice mantle, and makes some assumptions about how globally contiguous of a unit it is. I'd be interested to see if some of the first papers to come out on Ceres from the Dawn data will deal with the qualities of the mantle deduced from the imagery and the spectroscopy...

-the other Doug

[Bill Harris]

Even the crustal morphology of Ceres will prove to be engimatic.

By the Survey Orbit, Elevation maps were developed and they told a strange story. Ceres has a significant elevation relief of +/-- 7.5 Km around a zero datum. And it seems to be more relief than can be accounted for with a warm-ish icy crust without sagging down or up, back to the datum. But look at the distribution of elevations-- the highland areas are several discrete continents with the abyssal plains in between. Intuitively it would seem that the continental highlands are a low density, thick icy material floating isostatically on the higher density silicates of the upper mantle with the abyssal plains created by relict large impact craters. This is just arm-waving, and we'll learn more from upcoming gravity surveys and determination of the composition of the crust.

By terrestrial analogy, these are granitic crustal blocks bobbing about in basaltic ocean basins.

Illustrations:

A geomorphology map of Ceres showing surface features and continents and abysses:
https://univ.smugmug.com/Dawn-Mission/Ceres...geomorph-v1.jpg

Elevation map, cylindrical projection:
http://photojournal.jpl.nasa.gov/catalog/PIA19606

Elevation map, hemispherical projection:
http://photojournal.jpl.nasa.gov/catalog/PIA19607

Global animation:
http://photojournal.jpl.nasa.gov/catalog/PIA19605

Be thinking about the distribution of surface features on these two crustal provinces.

--Bill

[Bill Harris]

A montage of SO and HAMO images of "Tall Mountain"

https://univ.smugmug.com/Dawn-Mission/Ceres...n_montage.png

--Bill

[Herobrine]

The terrain next to the young crater in today's HAMO release is some of the strangest I've seen on Ceres to date. I don't really know what to make of it.

It's times like these that I wish I'd paid more attention to the moons of the gas giants so I might have something to compare it to.

From http://photojournal.jpl.nasa.gov/catalog/PIA19882

[Habukaz]

The interior of the crater looks rather interesting, too. The bright streaks running down the crater walls, and patches of smooth(er) floor terrain. Guess it's a relatively young crater.

[ZLD]

Processed enlargement of HAMO 6.


(click to enlarge)

Any ideas on the rough patch on the northern side of the crater rim? Strange feature I haven't seen before.

Floor of the crater is really interesting with a sinuous path of something...

On the northern outside of the crater, appears to have been a landslide, while the south side looks like it has slumped some but also looks like it could have been caused by a much less viscous flow into the nearby depression.

Very rough on the western edge as well. This seems pretty consistent with other craters with the white material.

[Betelgeuze]

Looking at the latest pictures I sometimes wonder if Ceres is just full of sinkholes

[Bill Harris]

HO-6 is related to Survey Orbit image SO-22 and is located NE of the crater Toharu. It is an unusual Facula because it is located on a Highland area and not on a Lowland plain. This type of bright spot is evidently related to impact ejecta disturbing a zone of light-toned material, whereas the other type of Facula may be related to be an effusive process related to hydrothermal activity.

And looks to be a lot of mass-wasting (slumping) around this crater. And if you look closely there is a lineation (and possibly a line of craters) on the NW rim, cutting through alluvial fans at floor level.

https://univ.smugmug.com/Dawn-Mission/Ceres...s3x--enh2-L.png

Just an arm-waving guess, seeing how the puzzle-pieces are fitting together.
I'll also guess that the Haulani crater area will be up within the next couple of orbits.

And this, the Third Day of HAMO...

--Bill

[Habukaz]

Ah, now it strikes me that this area is very similar in appearance to the trough-shaped "appendage" of the crater from the previous HAMO image (they are both roughly rectangular).



It does indeed look like it could be a landslide of sorts, one that went away from the crater rather than into it. The end result is a locally (relatively) symmetric crater wall, with slopes of similar steepness on both sides of the crater rim.

This topographic feature (note the shadows), partially shown in the previous cropped image, is also very interesting . My eyes want me to believe that there is an overhang in the middle there (the part with a "finger" sticking out), but I don't know if that's even possible to tell from this image.



And, uh, isn't that a plateau on the crater rim? I am starting to like this crater.



As for the overall appearance of the crater, I am reminded of the way crater ejecta on Mars is interpreted: certain ejecta blankets are thought to be caused by subsurface water. Since Ceres is supposedly full of water, it makes sense to me that impacts here may temporarily liquefy water close to the surface and create a 'mud splash', as is thought to happen on Mars.

[alan]

It appears that there may be unevenly distributed bright material hidden below a regolith which is being revealed by landslides. The bright spots in the center of some of the craters may be just the most recent places where it has reached the surface.

[nprev]

Huh. There seem to be a fairly large number of mass-wasting events scattered around, all of which have a relatively fresh appearance. I wonder if Ceres' upper crust is somewhat fragile due to the presence of volatiles and the effects of solar heating; might not take much to trigger an avalanche, might take nothing more than enough solar exposure over time.

Oddly dynamic-looking little world, getting odder with every image.

[Gladstoner]

Some observations and thoughts on the recent HAMO release (some points mentioned in posts above):

1. The bits of white stuff in the upper parts of the crater wall are interesting as always. Similar features in craters on Vesta and Phoebe come to mind.

2. There is an almost complete (if not complete) lack of discernable craters of any size within the big fresh crater or its ejecta sheet. This is an indication of a very young crater, very recent mass-wasting events, or both.

3. The ejecta sheet has a degraded look to it. It is as if the material subsided or collapsed in places.

4. There is a straight linear feature (fracture?) running along the base of the wall from 9:30 to 11:30.

5. There appears to be a sinuous 'rille' running the length of the large valley on the north side.

[Bill Harris]

...

[ZLD]

Care to expand on that Bill? I've looked at the image with the gamma turned up already and didn't see too much to be revealed.

[MarsInMyLifetime]

I agree that this crater is clearly a relatively fresh impact crater, but I suspect it is too small to have been a cause for any fractures or visible changes to the surface other than the obvious ejecta and some later slumping indicated by the detritus in the basin. The crater south of Tall Mountain seems quite a bit different to me in that it has no obvious ejecta and the basin floor looks suspiciously like the plains surface surrounding it. I'm strongly reminded of the sinkholes here in the Texas limestone country where the surface texture pretty much collapses intact into failed caverns, and naturally with no upheaval/ejecta material around them. So that's in the back of my mind as I compare the two craters (and ponder what subsurface activity may also account for the formation of Tall Mountain beside it--I am now under the impression that all the large craters around Tall Mountain may in fact be linked by subsurface activity).

[ZLD]

Processed enlargement of HAMO 7.


(click to enlarge)

Can't say with any certainty but the feature at the top left in the image has a very large shadow for its apparent size and may be a slight overhang.

[pac56]

Some observations and thoughts on the recent HAMO release (some points mentioned in posts above):

1. The bits of white stuff in the upper parts of the crater wall are interesting as always. Similar features in craters on Vesta and Phoebe come to mind.

2. There is an almost complete (if not complete) lack of discernable craters of any size within the big fresh crater or its ejecta sheet. This is an indication of a very young crater, very recent mass-wasting events, or both.

3. The ejecta sheet has a degraded look to it. It is as if the material subsided or collapsed in places.

4. There is a straight linear feature (fracture?) running along the base of the wall from 9:30 to 11:30.

5. There appears to be a sinuous 'rille' running the length of the large valley on the north side.

The feature at 9 o'clock (number 3) reminds me of "half Tall Mountain". Tall Mountain is also very close to the rim of a crater. Could it be that the impacts lifted part of the surface à la pingo? Maybe the angle of impact makes a difference?

[Bill Harris]

HAMO-7 is an example of crater internal slumpage:

http://photojournal.jpl.nasa.gov/catalog/PIA19883

The large crater is Toharu

--Bill

[Landru79]

ZLD:
Can't say with any certainty but the feature at the top left in the image has a very large shadow for its apparent size and may be a slight overhang.

I think the crater in the center of HAMO 7 is Toharu and the shadow on its left another big one


http://foro.sondasespaciales.com/index.php...1.msg130295#new

[ZLD]

Processed enlargement of HAMO 8.



Seems the compression is much higher on this image than the past several HAMO TIFFs. Not sure why.

Not many new revealing items in this release. One feature of note is the bright spot, previously visible as just a white blob in SO10, SO19, SO40, SO42, is indeed a crater, very similar in appearance to Haulani and other craters with the white material, just on a much smaller scale. Also, another crater to the north that is caving inward.

[hendric]

Please, tell me I am going crazy, there is no way Toharu is really a wide-area of sinking ground... But...The amount of correspondence is just downright creepy...

[ngunn]

Processed enlargement of HAMO 8.
One feature of note is the bright spot, previously visible as just a white blob in SO10, SO19, SO40, SO42, is indeed a crater

Well I'd say that feature is very interesting indeed. At last we see clearly the crater within one of these small white spots. Not only that, but where there would normally be a pitch black shadow inside it we see details backlit by light from the sunlit part of the interior.

[ZLD]

Took me a bit to understand why you painted a white line on the image Hendric then I realized finally that you cut and moved a section of the crater floor. This seems to lend some evidence to sinkholes being on Ceres. Based on other (suspected) impact craters with a lot of slumping, it could also be the result of an impact meeting a certain energy threshold that causes the surface to destabilize. Maybe the soil is made up of solidified mud with locked up water crystals that, when heated from a large enough impact, get released and sublimate away, leaving the soil very brittle and likely to collapse. Could also be driven by an annual cycle.

I know it isn't planned but I hope that when the mission is done and Dawn is left in it's final orbit, that they can drum up some support for a Cerian Summer mission. Would definitely bring some insite into how an ice body behaves at the frost line.

[charborob]

If anybody has some free time, here's a suggestion for a project: trace the outlines of the published HAMO images on a map of Ceres.

[Bill Harris]

Is there any reason you cannot do it? You've got many anagrams and panoramic mosaics on the forum.

[ZLD]

Its funny you mention that charborob. Already had started this yesterday.


(click to enlarge)

HAMO 4 doesn't fit super well since it is so far north, so I've just noted it slightly to the southwest of its location. I'll get it fit eventually but my map skills are lacking. HAMO 8 hasn't yet been traced but I noted the location on there.

[charborob]

Thanks, ZLD. That's exactly what I was thinking about. I could have done it myself, but I don't have any time to spend on this project. Maybe you could post your updated map once in a while.

[ZLD]

I plan to update it with each HAMO release so I'll just include it with those.

[Habukaz]

Interesting fissures in the latest image. I had some trouble locating the crater, but it lies south-west of Occator and is visible e.g. in Survey image 11 (there is a characteristic pawprint to its north-west that makes it easier to recognise).

An interesting question is where its bright stuff comes from - is there a fresh crater just outside the frame?

[ZLD]

Processed enlargement of HAMO 9.


(click to enlarge)

I also had a lot of trouble finding this crater. I tried your suggested location Habakuz and it looks similar in SO11 but on the map, it doesn't seem to line up at all. Maybe I'm missing something.

Edit: It was the same area you mentioned in SO11, Habakuz. A slightly better lit capture is in SO48, at the very right edge near the top. On the map, the area is somewhat blurry so it was difficult to tell what was going on.


(click to enlarge)

Survey orbit locations are simple approximations.

[charborob]

Interesting slump or flow around the 4 o'clock position on the inside crater rim.

[ZLD]

Also looks like the start of a massive slump here.

[Habukaz]

A slightly better lit capture is in SO48, at the very right edge near the top. On the map, the area is somewhat blurry so it was difficult to tell what was going on.

That looks like it, yes. No obvious sign of any bright, smaller impact crater nearby from that angle, either; which is interesting (or have we already seen something similar elsewhere in the solar system?).

[Bill Harris]

I plan to update it with each HAMO release so I'll just include it with those.

Thanks-- that spotting the HAMO images on the cylindrical map is a major (but burdensome) intitial task in plotting their footprint on the SO-imagery.

--Bill

[HSchirmer]

(or have we already seen something similar elsewhere in the solar system?).

Perhaps this is similar to the Java mud volcano

Theories are that it was triggered when drilling breached the surface clay,
which let out mud and gas beneath.
http://www.berkeley.edu/news/media/release...6/09_lusi.shtml

Interesting thing, the area may be sinking into a sort of caldera.

Tons of pictues
http://www.crisp.nus.edu.sg/coverages/mudflow/

Attached thumbnail(s)

 

[ZLD]

Processed enlargement of HAMO 10.


(click to enlarge)

Doesn't seem to be much new to note here. Several very fresh looking craters scattered in this area.


Imaging map with HAMO 10 near the Toharu crater once again.


(click to enlarge)

Looking at the typical progression of images, there should be a good nadir position for capturing Occator for the next orbit but who knows if they'll release it or not.

[Daniele_bianchin...]

In september 2013 a new island formed by a 7.7 pakistan earthquake; The island is a mud volcano that had been caused by an emission of methane gas on the seabed.it resemble a big mount over Ceres:

[Bill Harris]

HAMO image HO-10 is noteworthy because it straddles two major Cerean terrains.

https://univ.smugmug.com/Dawn-Mission/Ceres...2--orient-L.png

--Bill

[RotoSequence]

In september 2013 a new island formed by a 7.7 pakistan earthquake; The island is a mud volcano that had been caused by an emission of methane gas on the seabed.it resemble a big mount over Ceres: http://eoimages.gsfc.nasa.gov/images/image...erial_photo.jpg

Hmm. Good catch! The same mud volcano, from above:

[Habukaz]

Perhaps this is similar to the Java mud volcano

Theories are that it was triggered when drilling breached the surface clay,
which let out mud and gas beneath.
http://www.berkeley.edu/news/media/release...6/09_lusi.shtml

Interesting thing, the area may be sinking into a sort of caldera.

Tons of pictues
http://www.crisp.nus.edu.sg/coverages/mudflow/

Primarily thinking about the bright stuff scattered around the crater - not quite sure how this would relate to it. We have seen plenty of bright impact crater elsewhere in the solar system, but I don't recall seeing older craters with specks of bright stuff around them (but I guess it could simply be the last remnants of a more massive cover of bright stuff that the crater once was surrounded by).

[Bill Harris]

New images to Ceres Gallery, including a study of a crater-facula in HAMO-8, stereo imagery in SO-24,-25, and episodic emplacement of fluidized flows in HO-4.

https://univ.smugmug.com/Dawn-Mission/Ceres

What a quirky little world.

--Bill





I am a traditionalist-- I like to do image montages ("stitching") and stereo pairs manually. But yesterday I finally broke down and got a copy of Stereo Photo Maker (freeware and a dang good program-- support your local developer!!) and last night I redid the two SO-24,-25 stereo pairs noted above. Enjoy.

--b

[ZLD]

Processed enlargement of HAMO 11.


(click to enlarge)


Imaging location map.


(click to enlarge)

It took me a while to realize that HAMO 11 was located right in the middle of SO4. Smacked my forehead on that one. No further updates on SO locations with this one.

[Guest_Steve5304_*]

images of spot 5 are being held from the public because of a peer review pending paper. Im told that the new pictures are wonderful and reveal alot the spots appear to be resembling a lake bed and some sort of dusting material all over the place in and out. The material is still not known..tho its openly being speculated its some sort of new element. something we dont know about yet. It may be many more weeks before occator images are released.

[stevesliva]

The material is still not known..tho its openly being speculated its some sort of new element.

unobtanium or ice-9, definitely.

[Guest_Steve5304_*]

unobtanium or ice-9, definitely.

heh..maybe its elerium

whatever it is supposedly lt doesnt subliminate and yet is above the crater. but its not ice and not salt :shrug:


who knowsyet. the embargo on the images by nature mag it sucks