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Rosetta scientific results
Phil Stooke
post Jan 22 2015, 07:13 PM
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Great stuff, wonderful results - and maps showing the naming convention being developed. I imagine those name illustrations will show up on the Rosetta site.

Phil



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Explorer1
post Jan 22 2015, 07:24 PM
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One of the supplements (Morphological Diversity) gives the following:

QUOTE
The regions on comet 67P/Churyumov-Gerasimenko are given names of ancient Egyptian deities. The regions on the “head” part are given female names whereas the regions on the “body” and “neck” are assigned male names
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belleraphon1
post Jan 22 2015, 11:46 PM
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Fantastic papers and image release...

Remember in 1965 waiting for the Sky & Telescope edition that would report on Mariner 4 images from Mars.
Now 50 years later I can sit on my couch using my 10.1 inch tablet to wander the Lovecraftian landscapes of a worldlet.

How cool is that... smile.gif

Craig

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algorimancer
post Jan 23 2015, 03:29 PM
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It occurs to me that, if the RSI were focused on a point on the surface, and has sufficiently fine time resolution, it might be feasible to perform remote seismology studies (similar to helioseismology). Passive observation of reflected solar radiation might be sufficient, or it might require active transmission and simultaneous monitoring of the response. It would be really neat to hear the internal sounds of an active comet. Presumably Philae would have provided more direct measurements of this.
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SpaceScout
post Jan 24 2015, 12:43 PM
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QUOTE (Paolo @ Jan 22 2015, 07:57 PM) *
here you go! today's Science has a first batch of Rosetta @ CG papers!
http://www.sciencemag.org/content/347/6220.toc


the Science cover is just... wow!!!!!!


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katodomo
post Jan 24 2015, 03:30 PM
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I don't know if people noticed, but for MIRO the Acknowledgement in one Science article notes at which exact date data for the instrument will be deposited in PSA and PDS - 19 May 2015.
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Paolo
post Jan 28 2015, 07:22 PM
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more goodies, from Nature this time: Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years
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mcgyver
post Jan 29 2015, 07:13 PM
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I think nobody is talking about this here, but I think it's an amazing scientific result: Rosetta detected 350 micro-asteroids orbiting around 67P!!

QUOTE
considering measurements made with both GIADA and OSIRIS on 4 August 2014, when we were still at 275 km from the comet. These observations allowed us to count about 350 grains in bound orbits around the comet nucleus, and 48 fast, out-flowing grains that were ejected about a day before the observations.

http://blogs.esa.int/rosetta/2015/01/22/gi...nts-3-7-3-4-au/

Supplemental material gives more details: microsatellites were detected not by the dust grain detector (GIADA) but by the OSIRIS camera:
QUOTE
We consider OSIRIS-NAC images (2048 x 2048 px) taken on 4 August 2014 from 3h49UT to 5h53UT at 3.6 AU from the Sun. These images are taken in sets repeated 5 times, with an interval of 26 minutes between each set. Each of these 5 sets contains 5 images with an exposure of 17.25 s taken every minute using the NAC's orange filter (centred on 649 nm, 84.5 nm wide).

(so we have at least 25 hires images awaiting for release smile.gif )

QUOTE
In the composite image, covering a time interval of 197.25 s, every moving object appears as a sequence of white, black, white and black tracks (fast moving grains) or dots (slow moving grains), thus allowing us to define its apparent speed and direction of motion


QUOTE
. Assuming a mean albedo of 5%, we get a diameter range from 0.2 to 2 m for grains at the outermost limit of the grain cloud (at about 600 km from the spacecraft; the size of 2 m is a crude upper limit: it assumes that the brightest grains are also the farthest); and from 4 to 40 cm for grains at 130 km from the spacecraft
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Bill Harris
post Jan 29 2015, 08:45 PM
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QUOTE
diameter range from 0.2 to 2 m
Whoa. I only did a quick initial scan the Rotundi, et al paper, but those grains are HUGE. I was thinking mm- to cm-sized particles. They are likely silicate/organics (doubtful with any ice) "fluffballs".

-Bill


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elakdawalla
post Jan 29 2015, 09:18 PM
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At AGU Sierks showed one of the photos with this "snow" of particles in bound orbits. A few looked exactly as described in the paper -- alternating bright and dark, which he said you could use to determine their spin rate. So far we've pretty much only seen releases of OSIRIS images of the nucleus, none of these aimed at particles near the nucleus. I can't wait for the data set release to examine those.


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Sherbert
post Feb 2 2015, 11:45 PM
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Related to the OSIRIS team morphology results. Here are some selections from the recent Lander Search image. I have tried to find examples of the types of terrain highlighted in the reports. To keep this post short my comments, guesses and theories(?) are given in the image descriptions.

https://www.flickr.com/photos/124013840@N06...in/photostream/

https://www.flickr.com/photos/124013840@N06...in/photostream/

https://www.flickr.com/photos/124013840@N06...in/photostream/

https://www.flickr.com/photos/124013840@N06...in/photostream/

I'm no geologist, so any suggestions/admonishments by those more qualified would be appreciated. Certainly Bill H. knows a whole lot more than me about this subject and no doubt Emily is writing a blog about this OSIRIS image for the Planetary Society right now. smile.gif
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Jackbauer
post Feb 9 2015, 07:02 PM
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http://blogs.esa.int/rosetta/2015/02/09/se...sts-for-67pc-g/

Scientists from Rosetta’s OSIRIS team have been analysing the images of Comet 67P/Churyumov-Gerasimenko and comparing them to a thermal model to estimate how much material the various parts of the comet will lose through Sun-driven sublimation during one orbit. That is, as the Sun heats the comet, ices sublimate and the resulting gases drag dust into the comet’s coma
(…)

“Assuming that four times more dust is emitted than ice, our model leads to very different scenarios for the northern and southern hemisphere,” says OSIRIS scientist Stefano Mottola from the Institute for Planetary Research of the German Aerospace Center (DLR). “While during its short but intense summer the southern hemisphere may lose a surface layer measuring up to 20 metres in thickness, this value should be much smaller for the northern hemisphere. According to our estimations, only very few prominent peaks and cliffs may erode by more than ten metres over the course of one orbit.”
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MargaritaMc
post Feb 9 2015, 08:15 PM
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The Max Planck Institute for Solar System Research press release is at this URL
Rosetta: Comet’s South Heats Up


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ngunn
post Feb 9 2015, 09:27 PM
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The fact that the south side sublimes away faster than the north because it is facing the sun at perihelion provides a possible reason for the asymmetric position of the neck, offset from the centre line between the two lobes. When the contact binary formed the neck would have been on the centre line but the missing material has left it off to one side, giving the duck a north facing 'chin'. This narrative implies that at perihelion mass loss will occur more from the lobes than the neck, contrasting with what we see now as the northern hemi-object is illuminated. Let's see if that happens.

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Gerald
post Feb 9 2015, 09:45 PM
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Regarding mass loss in the neck region they've a backdoor:
QUOTE
The neck area between the comet’s two lobes is particularly weakly insolated. At the same time, it has displayed the strongest and earliest dust activity in the past months. The scientists therefore believe that possibly this region has a different composition than the rest of the comet.

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.
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