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Ceres Low-Altitude Mapping Orbit (LAMO)
dvandorn
post Aug 10 2016, 07:57 PM
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The presence of clays implies rock altered in an aqueous environment. With proposed subsurface liquid water deposits, either ancient or current, within each of these bodies, I am thinking it's not difficult to understand how such clays form. How they got to the surface, that's another matter, though I imagine impacts have had something to do with it...

-the other Doug


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charborob
post Aug 11 2016, 04:12 PM
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LAMO images 146 and 147 stitched together:
Attached Image
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Don1
post Aug 27 2016, 08:51 AM
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From GSA meeting abstracts:
"CERES EVOLUTION BEFORE AND AFTER DAWN"
" In this new study we propose one possibility is that Ceres accreted as an ice and silicate mixture after short-lived radionuclides in CAIs had significantly decayed, i.e. nearer 5 my after CAIs, and thus differentiated less completely than for hotter models. On the other hand, the presence of heavily aqueously altered mineralogies, including probably salts, suggests extensive mixing of water and silicates, which might normally be associated with more complete differentiation. Geologically recent activity, perhaps even to the present time, seems evident from several young landforms, including protrusions consistent with diapirism and recent exposures of water ice...The presence of ammoniated minerals and what appear to be salt deposits suggest a major lowering of subsurface water ice melting temperature,."

"SURFICIAL COMPOSITION OF DWARF PLANET CERES"
"... presence on the surface of a mixture of dark carbon-rich minerals, Mg- phyllosilicates, ammoniated clays, and carbonates [4]...[bright spots] are mostly consistent with a large amount of carbonate, implying recent hydrothermal activity "

My comment: A recently active hydrothermal site would be a nice place to visit with a lander!

"ELEMENTAL CONSTRAINTS ON CERES' EVOLUTION"

"[Gamma ray spectrometer] data show that Ceres’ regolith is hydrogen rich, with an equatorial composition (Fe, K, C) similar to that of aqueously altered CI/CM chondrites."

My comment: The famous Murchison meteorite is a CM chondrite.
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Explorer1
post Sep 1 2016, 06:36 PM
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Looks like Ahuna may be volcanic after all! A tenuous, temporary atmosphere was detected as well.

http://www.jpl.nasa.gov/news/news.php?feature=6611
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Daniele_bianchin...
post Sep 1 2016, 08:18 PM
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Now that we know the composite and internal structure of ceres, we can exclude a possible liquid salt water layer under its surface?
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Gladstoner
post Sep 2 2016, 07:48 PM
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Evidence of water found in Oxo Crater:

Attached Image


http://photojournal.jpl.nasa.gov/catalog/PIA20916

The indicated area of water-ice detection appears to be near the toe of the massive wall slump. Example of a rotational slump:

Attached Image


Perhaps the ice was recently brought to the surface by the slump movement. If so, this could indicate the presence of ice just below the surface in many areas (that hasn't yet sublimated due to long exposure).
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Daniele_bianchin...
post Sep 24 2016, 08:05 AM
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QUOTE (Daniele_bianchino_Italy @ Sep 1 2016, 08:18 PM) *
Now that we know the composite and internal structure of ceres, we can exclude a possible liquid salt water layer under its surface?

?
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nprev
post Sep 24 2016, 05:53 PM
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Danielle, to my knowledge there have been no conclusions published in peer-reviewed scientific journals to that effect one way or another. Certainly no authoritative opinions concerning that or any other attribute of Ceres (or any other body) are to be derived from our discussions here. UMSF is not a peer-reviewed scientific journal.


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Gladstoner
post Sep 26 2016, 06:12 PM
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QUOTE (Daniele_bianchino_Italy @ Sep 1 2016, 03:18 PM) *
Now that we know the composite and internal structure of ceres, we can exclude a possible liquid salt water layer under its surface?


The short and general answer is probably no. There is likely a diffuse 'wet' zone between the surface regolith (and underlying megaregolith?) and the denser lower mantle and core. The water probably occupies pore spaces between grains and along structural breaks such as fractures. Roughly speaking, this could be thought of as a liquid salt water layer. On the other hand, the lack of isostatic adjustment of surface features and the extensive presence of 'rocky' material at the surface seem to preclude or severely restrict the presence of any 'free standing' layer of water, brine, or ice.
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Daniele_bianchin...
post Sep 27 2016, 09:15 AM
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QUOTE (nprev @ Sep 24 2016, 05:53 PM) *
Danielle, to my knowledge there have been no conclusions published in peer-reviewed scientific journals to that effect one way or another. Certainly no authoritative opinions concerning that or any other attribute of Ceres (or any other body) are to be derived from our discussions here. UMSF is not a peer-reviewed scientific journal.


I know, but here they write people very competent, in a scientific manner; and realistic. Certainly, they are waiting 'public conclusions. In this Forum, there is little imagination, and a lot of reality ', and I like this;
Many thanks

QUOTE (Gladstoner @ Sep 26 2016, 06:12 PM) *
The short and general answer is probably no. There is likely a diffuse 'wet' zone between the surface regolith (and underlying megaregolith?) and the denser lower mantle and core. The water probably occupies pore spaces between grains and along structural breaks such as fractures. Roughly speaking, this could be thought of as a liquid salt water layer. On the other hand, the lack of isostatic adjustment of surface features and the extensive presence of 'rocky' material at the surface seem to preclude or severely restrict the presence of any 'free standing' layer of water, brine, or ice.


Many Thanks for your opinion 'Gladstone'
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JohnVV
post Sep 30 2016, 01:49 AM
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"And now for something completely different ..."

it has been a bit since i did a 3d rendering of a crater on Ceres
release #170 "PIA20932"
http://photojournal.jpl.nasa.gov/catalog/PIA20932




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JohnVV
post Sep 30 2016, 04:19 AM
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image release #172 "PIA20934"
http://photojournal.jpl.nasa.gov/catalog/PIA20934

has a nice slump/wasting of a rim



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