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Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE !
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[quote:Anonymous Coward 29634328:MV8yNTk4OTk2XzUwNTg2NzYxXzM4RjRGNTU1] [b]New Coma Discovery[/b] There is an interesting new paper here http://www.aanda.org/articles/aa/pdf/forth/aa25925-15.pdf hosted on this page http://www.aanda.org/component/article/?access=doi&doi=10.1051/0004-6361/201525925 from Paul Felman et al. concerning a new discovery in coma chemistry. It had been assumed that the daughter species products of the comet volatiles, gasses like H1,O1,OH and C1, were produced by the photodisociation of the parent molecules such as H2O and CO2. The paper "Measurements of the near-nucleus coma of comet 67P/Churyumov-Gerasimenko with the Alice far-ultraviolet spectrograph on Rosetta" outlines a different mechanism for producing the daughter species. Once molecules of water or CO2 have been photoionised, by energetic UV photons from the Sun, the ejected electrons go one to collide with other gas molecules in the coma. The electrons have energies in the range 25 to 50 eV, that is sufficient to cause electron impact dissociation of water and CO2 into their daughter products. This discovery neatly explains a puzzle of comet 67P's coma. At this distance from the Sun, very few photodisociation events should occur and yet the ( apparent ) daughter products of photodisociation are abundant. THe team made use of data from the VIRTIS-H spectrometer to confirm relative abundances, MIRO and ROSINA to correlate production rates and OSIRIS and NAVCAM to confirm where ALICE was pointed. One particularly useful sample was taken on the 29th November when NAVCAM confirmed that ALICE was pointing at the shadowed neck region. Measurements of Lyman alpha and beta emission lines could be gathered, free from the background Ly-alpha signal of interplanetary space. The ratio of Ly-alpha to Ly-beta intensities was consistent with an electron impact dissociation emissions. blog post http://blogs.esa.int/rosetta/2015/06/02/ultraviolet-study-reveals-surprises-in-comet-coma/ with helpful diagram http://www.esa.int/spaceinimages/Images/2015/06/Rosetta_uncovers_processes_at_work_in_comet_s_coma P.D. Feldman et al. (2015) Measurements of the near-nucleus coma of comet 67P/Churyumov-Gerasimenko with the Alice far-ultraviolet spectrograph on Rosetta. [i]Astronomy and Astrophysics[/i] http://www.aanda.org/component/article/?access=doi&doi=10.1051/0004-6361/201525925 The Rosetta program is expected to cost around 1.3bn euros. That's not the same as making a big bonfire of money or blasting a pile of cash into space. That money has gone into supporting Airbus Defense & Space ( Astrium ) and Arianespace as well as a host of small companies and universities and research institutes all across Europe ( and beyond ). Spin off technologies include a miniaturised gas chromatograph that Colin Pillinger and the team at the OU developed for Ptolemy, that has gone into environment monitoring equipment for Astute class submarines and will find many more applications. I am sure the LILT ( Low intensity, Low temperature ) solar cells developed for Rosetta will find a role in tele-monitoring / survival applications at high latitudes. Rosetta spacecraft thermal control system has already found its way into everyday satellite applications. One important reason to do the Rosetta program is for the prestige and to lay down a marker. At the time Rosetta was first proposed, ESA had only been in existence for a few months. The agency was looking for possible future missions that would challenge European aerospace to develop new technologies and rival the missions that only NASA and the Soviet programme could accomplish. It would be many years and a number of false starts before ESA was in a position to launch the Rosetta mission. If you asked any of the scientists why do the Rosetta mission I am sure they would say it was to make new discoveries, to resolve the mysteries of comets and contribute to sum of scientific knowledge. The mission is supposed to break new ground and discover new things. If it didn't we would all feel cheated. This brings me to one of GLPs favourite memes. Any time scientists have made a new breakthrough or discovery, remember that is what they are supposed to do, they are described as being shocked and baffled. So with that in mind here is a scientist checklist list for "H1 and O1 in comets comes from electron impact disociation and not photodisociation" Scientists are: Interested | X Intrigued | X Mildly Surprised | X Baffled | Shocked | Moving Tomatoes | Watchin YouToobs | Nibiru!!! | Zetas right again | K [/quote]
Original Message
I want to use this thread to highlight news from the Rosetta comet mission.
Ten years ago the European Space Agency ( ESA ) launched the Rosetta comet chaser to rendezvous with comet 67P, go into orbit around it and land a probe on its surface.
120 Icy Patches - by last September
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 69)
thanks FBVA
Philae Phones Home
Great news, thanks F-BVFA
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 68)
Ceres fly over video
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 67)
New Coma Discovery
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 67)
Pictures MOTHER LODE !
- There are
hundreds
thousands of images from Rosetta, this post will always point to the most recent NAVCAM or OSIRIS picture. Updated several times per week. ( Thanks F-BVFA )
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 67)
Ceres Spot Shot
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 66)
Potato
Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 66)
When the Rosetta mission is complete we will know so much more about comets, their composition and formation. Comets have been a cause of fear and fascination throughout human history, within the next few months many long standing mysteries will be solved.
K
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