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Huygens News Thread, News as and when we find it
Stu
post Jan 14 2010, 02:56 PM
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Five years... cripes... If I remember correctly, I was giving an Outreach talk in a junior school at the time of the landing, a "Tour of the Solar System", and when it came to Saturn I showed the classic old Voyager pic and told the class "By the time you go home we'll have pictures of this world's surface"... After the talk I rushed back to my mother's house, just a stone's throw from the school (as the little *******s proved more than once!), to go online and see the pics. That really was something, seeing the surface of a world I'd seen countless hundreds, maybe even thousands of times, through my small telescope. Those Huygens images turned a point of light into a real world for me. Next time that will happen will be when NH reaches Pluto... smile.gif


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ustrax
post Jan 14 2010, 04:21 PM
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QUOTE (Stu @ Jan 14 2010, 02:56 PM) *
Five years... cripes...


Yep, half a decade my friend... smile.gif
I also remember that special day...I went rushing home to see the images but knowing that I wouldn't see them as they reach the internet I saw this deserted public internet outpost and there I stand, seing a whole new world unveiling before our eyes. What a night! smile.gif


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ugordan
post Jan 14 2010, 04:59 PM
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QUOTE (Stu @ Jan 14 2010, 03:56 PM) *
Next time that will happen will be when NH reaches Pluto... smile.gif

Dawn not good enough for you? wink.gif

I remember the Huygens landing well, woke up early (didn't really get much sleep at all) and skipped college lectures that day just to watch the live ESA event (and via a NASA TV webcast at that!). The most emotional moment for me was when the Green Bank Telescope acquisition of Huygens carrier was announced and there were Huygens people literally crying with joy. That was it, the probe survived reentry and was working! It could only get better from then on. Actually seeing the first surface image in the evening that day, I had a hard time bringing myself to actually believing it. I frequently wish there was a recording of the live event somewhere, I'd like to live through it all again.


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eoincampbell
post Jan 14 2010, 05:56 PM
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The DISR movie on the ESA site really is a thing of beauty (tones too). smile.gif


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Stu
post Jan 14 2010, 06:00 PM
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QUOTE (ugordan @ Jan 14 2010, 04:59 PM) *
Dawn not good enough for you? wink.gif


Good point! smile.gif


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ngunn
post Apr 28 2010, 09:50 AM
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At long last, the un-annotated version of the Huygens landing site VIMS image appears in the latest CHARM presentation.
Attached File(s)
Attached File  Unannotated_VIMS_at_landing_site.doc ( 176K ) Number of downloads: 296
 
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titanicrivers
post May 13 2010, 12:59 AM
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From the CHARM slides its sounds as if a 3D-accurate mapping of Radar, VIMS and DISR (Karkoschka) is in the making!
In the meantime I've made a mapping with the CHARM VIMS image and Mikes T41 and T8 composite and the Vortex processed DISR (Karkoschka) image. Although not very bright in the final image I believe the 'enclosure' and the 'dude' arrowhead is visible and distinct in the Huygens channel.
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ngunn
post May 13 2010, 10:24 AM
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Aah - thanks for doing that. smile.gif smile.gif smile.gif I'd been doing it as well as I could in my head and come to the same conclusions. Now the question is what detailed spectral differences can VIMS pick out between 'dude' and 'interdude'? Also, can any 'cats eye' RADAR bright spots be identified or not? Then we just might be homing in on the likely composition of the pebbles. That paper when it comes out could be one of the most significant on Titan so far.
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ngunn
post Oct 8 2010, 09:58 PM
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I don't normally look at twitter stuff but these few from Emily might spark some discussion:

# Griffith: These are tiny, isolated regions with markedly different properties. Barnes still thinks she's wrong. #DPS2010 (about 1 hour ago)
# Barnes comment on Griffith paper: "This is good work, but to be honest I think it's wrong." #DPS2010 (about 3 hours ago)
# Griffith: Evidence in VIMS near Huygens site for liquids of depth less than 1 meter -- tropical puddles among dunes on Titan #DPS2010 (about 3 hours ago)

Huygens found quite a high level of methane humidity at the landing site, so both views seem plausible to me. Comments??
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centsworth_II
post Oct 8 2010, 11:57 PM
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QUOTE (ngunn @ Oct 8 2010, 05:58 PM) *
Huygens found quite a high level of methane humidity at the landing site, so both views seem plausible to me. Comments??

The first paragraph on page 186 here describes this.
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Juramike
post Oct 9 2010, 01:12 AM
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I've been reading up on drying clays (for fun), and also protein crystal structures (for work), and strangely enough there is a very common theme.

From what I understand, there are four types of bound solvent (water in the cases above):
Loose solvent: contained in macropores or interstitial spaces.
Tight solvent: the layers of solvent molecules immediately next to the surface (two molecular layers deep)
Bound solvent: solvent molecules actually localized and "pinned down" in a crystal lattice. These can be detected and localized in an X-ray structure. (Loose solvent molecules move around too much to localize by X-ray.) I'd classify clathrated methane as a "bound solvent".
Ligated solvent: these molecules (or portions of molecules - like a hydroxy for water) are actually coordinatively bound to an atomic center (usually a metal for a hydroxy) in the inner coordination sphere. There is electron density between the two coordinating atoms (oxygen giving it's lone pair to the metal center).

[For Titan's liquids: ligated solvent probably won't happen, with the possible exception of solvent nitrogen possibly coordinating it's lone pair or pi-orbital density to a massively elecrophilic center - maybe like a carbenium or carbonium ion. In the laboratory, reactive metals (CpCo(I)L2 f'r instance) are postulated to do this - I don't remember if it is side-bound (eta-1) or end-bound (eta-2) or both)]

The loose solvent evaporates quickly, but the tight solvent evaporates slower, and the bound solvent basically stays put. Once Huygens landed, the warm probe may have displaced some of the tight solvent and the bound solvent from the crystal lattice.

[Fun experiment at home, make Epsom salt crystals (MgSO4) by cooling a hot aqueous saturated solution of Epsom salt in a jar. Then take the pretty clear crystals (which have several waters of hydration in the lattice) and put them in the oven at low heat. They will come out all cloudy as the water of hydration is driven off. In the chemistry lab, I use MgSO4 (anhydrous) as a drying agent to suck water out of organic solution - when water gets reincorporated it releases noticable heat.]


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Juramike
post Nov 9 2010, 02:38 AM
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Article coming out in Icarus describes further analysis of Huygens probe penetrometer data (see Ralph's avatar for image of instrument).

Atkinson et al., Icarus (2010) Article in press. "Penetrometry of granular and moist planetary surface materials: Aplication to the Huygens landing site on Titan". (doi: 10.1016/j.icarus.2010.07.019
Abstract here (will be coming out in December of this year)

The authors examined the three stages of data.

1) The subtle ramp up to 2 ms, which they hypothesize is due to a thin (ca. 7 mm) coating of material weaker than terrestrial snow. (very fluffy stuff)
2) A sharp spike at 2 ms, which was reproduced in their experiments by "impacts with small pebbles or with hard crusts". For the pebbles, they felt that a 16 mm spherical particle was a match.
[I don't know if the hard crust possibility was investigated further.]
3) From 2.5 ms to 11 ms, there is a decreasing force tail, implying a decreasing resistance. This was a closest match with wet sand, with dryer sand up near the surface, and wetter sand below. However, the authors point out that even terrestrial wet sand isn't a perfect match. It seems as if Titans soil become even less resistant with depth compared to the wet sand analog.

Here is a graphic that sums up the results showing a hypothetical cross-section at the Huygen's landing site:
Attached Image


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B Bernatchez
post Oct 11 2012, 05:28 PM
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New animation of the Huygens landing and analysis of the ground where it landed was released today at http://www.esa.int/esaSC/SEMJP13S18H_index_0.html
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MarcF
post Oct 12 2012, 12:11 PM
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"Since the dust was easily lifted, it was most likely dry, suggesting that there had not been any ‘rain’ of liquid ethane or methane for some time prior to the landing."

This seems to be in contradiction with earlier results showing the presence of liquid methane in the soil, close to the surface.
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centsworth_II
post Oct 12 2012, 01:40 PM
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QUOTE (MarcF @ Oct 12 2012, 08:11 AM) *
This seems to be in contradiction with earlier results....
The article also quotes: "...the probe likely encountered a pebble protruding by around 2 cm from the surface of Titan, and may have even pushed it into the ground, suggesting that the surface had a consistency of soft, damp sand..."

Rather than a contradiction, I see this more as a refinement between wet sand and damp sand models. Even the first description after the landing - creme brulee - suggested a dryer surface over a wetter interior.

The statement: "...suggesting that there had not been any ‘rain’ of liquid ethane or methane for some time prior to the landing" is vague. Days? Months?
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