Rosetta scientific results |
Rosetta scientific results |
Jan 22 2015, 07:13 PM
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#16
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Solar System Cartographer Group: Members Posts: 10229 Joined: 5-April 05 From: Canada Member No.: 227 |
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 -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jan 22 2015, 07:24 PM
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#17
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Senior Member Group: Members Posts: 2106 Joined: 13-February 10 From: Ontario Member No.: 5221 |
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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Jan 22 2015, 11:46 PM
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#18
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
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... Craig |
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Jan 23 2015, 03:29 PM
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#19
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Member Group: Members Posts: 656 Joined: 20-April 05 From: League City, Texas Member No.: 285 |
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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Jan 24 2015, 12:43 PM
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#20
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Junior Member Group: Members Posts: 31 Joined: 3-August 14 From: Germany Member No.: 7229 |
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!!!!!! -------------------- space scout
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Jan 24 2015, 03:30 PM
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#21
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Junior Member Group: Members Posts: 78 Joined: 20-September 14 Member No.: 7261 |
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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Jan 28 2015, 07:22 PM
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#22
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
more goodies, from Nature this time: Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years
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Jan 29 2015, 07:13 PM
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#23
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Member Group: Members Posts: 107 Joined: 1-August 14 Member No.: 7227 |
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 ) 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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Jan 29 2015, 08:45 PM
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#24
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Senior Member Group: Members Posts: 3008 Joined: 30-October 04 Member No.: 105 |
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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Jan 29 2015, 09:18 PM
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#25
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
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.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Feb 2 2015, 11:45 PM
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#26
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Member Group: Members Posts: 153 Joined: 20-December 14 From: Eastbourne, UK Member No.: 7372 |
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. |
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Feb 9 2015, 07:02 PM
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#27
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Junior Member Group: Members Posts: 27 Joined: 2-December 14 Member No.: 7359 |
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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Feb 9 2015, 08:15 PM
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#28
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Newbie Group: Members Posts: 4 Joined: 29-September 14 From: 28°16'7"N 16°36'20"W Member No.: 7268 |
The Max Planck Institute for Solar System Research press release is at this URL
Rosetta: Comet’s South Heats Up -------------------- "In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen |
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Feb 9 2015, 09:27 PM
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#29
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
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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Feb 9 2015, 09:45 PM
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#30
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
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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