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Rosetta - Early Orbital Operations at Comet 67P C-G, August 6, 2014 - November 13, 2014
Y Bar Ranch
post Nov 8 2014, 08:00 PM
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QUOTE (fredk @ Nov 8 2014, 10:49 AM) *
If it is a barbell, and if it formed by the joining of two bodies, I might expect the two to be more loosely connected than if it formed by the erosion of one body. In that case, around the time of greatest activity near perihelion I might expect differing jet reaction forces across the nucleus to lead to shifts in one body perpendicular to the line joining the two. That should lead to cracks (like we appear to have seen already) opening or closing near the neck. Depending on the details of the gravitational field and connection of the two joined pieces, we might even see vibrational modes - periodic opening and closing of cracks.

I can't wait for perihelion...

If it started from one body but got to its current state, I'm thinking the tidal forces between the two lobes could be enough to cause cracking and movement at the neck.
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nprev
post Nov 8 2014, 09:10 PM
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I think that gravimetric data derived from orbital analysis could probably resolve the question of whether it started out as a single body or not, but given the extremely weak field I'm not sure if Rosetta will be able to discern much about the internal mass distribution of each lobe.

Incredible image.


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jgoldader
post Nov 8 2014, 11:56 PM
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QUOTE (Sacha Martinetti-Lévy @ Nov 8 2014, 11:44 AM) *
Just one more, though I can't remember if Emily didn't linked it from her blog. But if not :
Comet 26 09 14 NavCam Mosaic vc par 2di7 & titanio44, sur Flickr


I guess it's time for me to make a swear jar.
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elakdawalla
post Nov 9 2014, 05:07 AM
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I haven't been posting these to my blog because Elisabetta and Marco's colorization work is so artfully done that almost no one realizes that it is not actual color, yet we don't know what the actual color of CG looks like. I am holding out hope that at some point we'll see an actual color product from OSIRIS. Until we see that, I hesitate to post these artistic impressions because I want to make sure I and my readers understand what the true color of the comet looks like (inasmuch as we ever see true color from spacecraft cameras).

But I do think it's awesome work!


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Explorer1
post Nov 9 2014, 06:02 AM
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The contrast in brightness between the brighter neck region and the lobes is real, though, isn't it? That's where the venting is happening so it's plausible...
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Sacha Martinetti...
post Nov 9 2014, 02:02 PM
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QUOTE (elakdawalla @ Nov 9 2014, 06:07 AM) *
I haven't been posting these to my blog because Elisabetta and Marco's colorization work is so artfully done that almost no one realizes that it is not actual color, yet we don't know what the actual color of CG looks like. I am holding out hope that at some point we'll see an actual color product from OSIRIS. Until we see that, I hesitate to post these artistic impressions because I want to make sure I and my readers understand what the true color of the comet looks like (inasmuch as we ever see true color from spacecraft cameras).

But I do think it's awesome work!


Indeed. I agree with all your words. Color in astronomy is a very complex subject. Even I am sure that their work is showing the 67P albedo better than the long B&W exposures (it was my point here.)

But yes, we are waiting the "true" calibrated color pictures from Osiris. Science is patience smile.gif

And thank you again for all your great work, Emily.
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fredk
post Nov 9 2014, 06:10 PM
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QUOTE (Explorer1 @ Nov 9 2014, 07:02 AM) *
The contrast in brightness between the brighter neck region and the lobes is real, though, isn't it?

I'd say definitely not - if you look at the original image, you can see that the contrast between the bright patch and the rest of the comet isn't very high. That's the bright patch at far left centre:

I'd call that a clear case of "artistic license"...
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neo56
post Nov 11 2014, 11:57 AM
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Top 10 of yet unpublished pictures taken at less than 10 km above the surface


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AndyG
post Nov 11 2014, 03:15 PM
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^ I need a bigger swear-jar.

Andy
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belleraphon1
post Nov 11 2014, 06:10 PM
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Wow...walking a worldlet.
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tolis
post Nov 11 2014, 06:59 PM
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The rugged landscape of 67P is reminiscent of how the early space artists depicted the surface of the Moon.

Compare, for example, this painting by Lucien Rudaux (1874-1947; same generation as Chesley Bonestell)

http://www.muttpop.fr/wp-content/uploads/2..._2_original.jpg

with the Top 10 above.

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machi
post Nov 11 2014, 09:45 PM
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One of the new "top 10" images is suitable for stereo composition with older NavCam image.
It's surroundings of the Cheops boulder. Resolution is ~0.7 m/pix.
Credit: ESA / Rosetta / NAVCAM, CC BY-SA IGO 3.0 / Daniel Macháček.





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Gladstoner
post Nov 11 2014, 10:12 PM
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QUOTE (tolis @ Nov 11 2014, 12:59 PM) *
The rugged landscape of 67P is reminiscent of how the early space artists depicted the surface of the Moon.

Ansel Adams also comes to mind.
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MahFL
post Nov 11 2014, 10:37 PM
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Those boulders in 3D look like they are made of large snowballs.
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Astro0
post Nov 24 2014, 10:43 PM
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ADMIN EDIT: Now that the Philae separation and landing(s) events have taken place, this looks like a good enough point to mark the next stage of Rosetta operations. Posts made after this event have been moved to a new thread.
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