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Rosetta scientific results
ngunn
post Feb 9 2015, 10:03 PM
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Yep, that statement fits. The southern face should experience most of the sublimation at perihelion, but the nothern face willl be most actve in the periods before and after.
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belleraphon1
post Mar 6 2015, 01:36 PM
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Not sure where to put this...

Introducing the NAVCAM image browser
http://blogs.esa.int/rosetta/2015/03/06/in...-image-browser/


"We are happy to announce that the first set of images from Rosetta's NAVCAM has now been made available to all scientific and public users via ESA’s Planetary Science Archive (PSA). This first batch of image data covers the period leading up to 2 July 2014, prior to Rosetta’s arrival at 67P/C-G. Further releases of image data will be made in blocks on a monthly basis henceforth, with the near-term aim to catch-up so that NAVCAM data will be publicly released six months after they are taken."
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Greenish
post Mar 6 2015, 02:55 PM
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Following Phil's link in another thread, looks like another batch of Rosetta papers coming soon, but of course even the abstracts are fascinating.

From agenda of European Geosciences Union General Assembly 2015

Rosetta: first results from the prime mission
Convener: Matthew Taylor | Co-Convener: Stephan ULAMEC
Orals / Mon, 13 Apr, 13:30–17:15 / Room Y5 / Tue, 14 Apr, 10:30–12:00 / 13:30–17:30 / Room Y5
Posters / Attendance Mon, 13 Apr, 17:30–19:00 / Red Posters


Lots there.
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Jackbauer
post Mar 17 2015, 09:11 AM
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From the 46th Lunar and Planetary Science Conference

http://www.hou.usra.edu/meetings/lpsc2015/pdf/sess103.pdf

http://www.hou.usra.edu/meetings/lpsc2015/pdf/sess631.pdf
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scalbers
post Mar 21 2015, 02:09 PM
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QUOTE (Gerald @ Feb 9 2015, 09:45 PM) *
Regarding mass loss in the neck region they've a backdoor:

If it's richer in CO2 or CO the neck region may lose mass, too.
Maybe they find out more detail about the compositional variations during the close flyby to come.


Is the neck region having a different composition really a sign of CG being a contact binary? Seems to me more like a single object with more ices near the center that are now exposed? This question was touched upon at a talk last evening by Joel Parker of the Southwest Research Institute (and the ALICE instrument).


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Gerald
post Mar 21 2015, 05:58 PM
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A contact binary would probably be more interesting, but I share your preference for exposure of fresh interiour material of a single object.
Once the outermost crust is lost, sublimation may progress faster in that area, resulting in forming the neck.
The sublimation process of a prestine rotating cometary nucleus may start either near the equator for a spin axis parallel to the orbital axis, or near one of the poles if the pole happens to be directed towards the Sun near perihelion (skipping other options).
Taking the equator version the rotation axis may change (or precess) due to a change of the axis of maximum moment of inertia due to preferred mass loss of the nucleus near the equator.
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scalbers
post Mar 21 2015, 06:09 PM
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This preferential sublimation process seems interesting to me in for example how it might be modeled. Good food for thought with Gerald's scenarios. It also seems plausible in explaining some other similarly shaped comets.


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MarsInMyLifetime
post Mar 22 2015, 03:54 AM
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What still keeps me from accepting the excavated neck story are the large pits on the main body that are closest to the crack in the neck. These have the appearance of some of the other vent pits on both bodies. If they are indeed expired vents, then they had to have formed earlier than the scree/talus that now spills into them from the head. They do not match the valley wall morphology further up the neck; they are positioned facing outward relative to the main body, and circular as if not influenced by earlier neck material. I just can't conceive a history of their formation relative to neck material deflation that would have been happening at the same time, were this a unified object rather than a piece rotated into place at a later era. I see the refill history of those pits as telling something about the sequence of activity/erosion in the neck.


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Paolo
post Mar 22 2015, 08:03 AM
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BTW, if you have access to Science the nitrogen discovery paper is here:
Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature
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algorithm
post Mar 22 2015, 08:13 PM
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I was thinking about the 'Contact Binary. and the 'Eroded Neck' theories going on and thought I would add my twopence worth in favour of the 'Eroded Neck. camp.

While browsing here http://blogs.esa.int/rosetta/2015/03/20/co...-6-hours-later/

This image

Attached Image


and this comment

"On the large lobe, another striking feature catches the eye: the Aten region, an elongated depression between Ash, to the left, and Khepry, to the right."

The difference between the smoother,elongated. central region compared to the left and right regions on the larger lobe, to my eye, also applies to the smaller lobe.

This would indicate the same process happened to both lobes together.

In other words they are the same object.
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DoF
post Mar 25 2015, 01:42 PM
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I'm not sure I understand that reasoning. If we assume that the perihelion passages reforms the surface of the bodies, then the main surface features of both lobes would have been shaped by the same process at the same time regardless of whether it's a contact binary or not. If it is a binary object then they presumably joined before becoming a comet after all. It might indicate that both lobes have similar/same composition, but not that 67p is necessarily a single object.
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algorithm
post Mar 25 2015, 07:14 PM
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Fair point!

The ratio between central area and left/right, also seems similar between the two lobes.....mmmmmmm...

So your rationale seems plausible for a contact binary. (As do others)

Lucky it's only twopence, but that's the beauty of armchair exploration. smile.gif

Game on !!
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katodomo
post Apr 13 2015, 09:12 AM
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Since we had a link to AGU webstreaming here's the European counterpart, albeit only with a single press conference streamed for Rosetta:

http://client.cntv.at/egu2015/PC1

Ulamec, Taylor and the PIs of ROMAP and RPC-MAG. Live on Tuesday, 1200 to 1300 UTC+2 (CEST).
Before that the stream will show previous press conferences (and something that looks like standup comedy in the press conference room in Austrian inbetween wink.gif )

The above stream link offers a chat function to submit questions for the press conference remotely.

Related speech at EGU 2015: http://meetingorganizer.copernicus.org/EGU2015/session/17358

Abstracts for all speeches on Rosetta at EGU 2015 today and tomorrow: http://meetingorganizer.copernicus.org/EGU2015/orals/17358
And, perhaps oddly, abstracts for the poster session: http://meetingorganizer.copernicus.org/EGU2015/posters/17358
(edit: those two already posted earlier in this thread, here for completeness.)
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DoF
post Apr 14 2015, 12:29 PM
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Thank you for the heads up katodomo, the stream is over but a video is now available. It deals mostly with Philae and the magnetic field of the comet, magnetic field information is also in a new Rosetta blog post (http://blogs.esa.int/rosetta/2015/04/14/ro...not-magnetised/).
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Paolo
post Apr 14 2015, 04:27 PM
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and the Science preprint: The nonmagnetic nucleus of comet 67P/Churyumov-Gerasimenko
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