Rosetta i fin form

Fora ASTRO-FORUM GENEREL ASTRONOMI Rosetta i fin form

Dette emne indeholder 218 svar, har 27 stemmer og blev senest opdateret af mikael_joe 3 år, 7 måneder siden. This post has been viewed 1414 times

Viser 15 indlæg - 196 til 210 (af 219 i alt)
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  • #124718

    Julius
    Deltager
    • Nova

    “Although the ovens worked correctly, the scientists do not yet know how
    much – if any – material was actually delivered to the ovens by SD2, or
    whether the instruments sampled dust or gas that entered the chamber
    during the touchdown.”
    http://blogs.esa.int/rosetta/2014/11/19/did-philae-drill-the-comet/

    MrJulius2014-11-19 18:55:43

    #125209

    Torben Taustrup
    Admin
    • Neutron star

    67P – P for potato

    67P er kartoffelformet Wink
    Jeg fik lige reddet den inden den blev skrællet. Efterfølgende er den indgået som en af
    1ngredienserne i en gryde skipperlabskovs.


    Torben Taustrup – ttau@tocobs.org – TOC Observatory – http://tocobs.org -12.5″ – f:5 Newt. Starlight XPress SXV H9 og Atik383 CCD-kamera. Fields: 19,6′ x 14,6′ Px: 0,84″ / 39,63 x 29,51 Px. 0,71″ – SkyWatcher 80 mm ED refraktor. TAL Apolar 125 f : 7,5.

    #125218

    edbbob
    • Super Nova

    Har du spist den?!? Hva så med Phil?

    #125220

    Torben Taustrup
    Admin
    • Neutron star

    Ups! Den havde jeg sgu ikke tænkt på Wink
    Jeg melder lige tilbage, hvis den på et senere tidspunkt skulle have sat sig fast mellem et par
    tænder. Det er nok det sted, hvor Solen skinner mindst.


    Torben Taustrup – ttau@tocobs.org – TOC Observatory – http://tocobs.org -12.5″ – f:5 Newt. Starlight XPress SXV H9 og Atik383 CCD-kamera. Fields: 19,6′ x 14,6′ Px: 0,84″ / 39,63 x 29,51 Px. 0,71″ – SkyWatcher 80 mm ED refraktor. TAL Apolar 125 f : 7,5.

    #125608

    nightsky
    Deltager
    • Neutron star

    Det kan man da bestemt kalde et spændende resultat. Vand på jorden kommer i hvert fald
    ikke fra kometer som 67P/Churyumov–Gerasimenko, og måske slet ikke fra kometer overhovedet.

    http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_fuels_debate_on_origin_of_Earth_s_oceans

    http://blogs.esa.int/rosetta/2014/12/10/rosetta-fuels-debate-on-origin-of-earths-oceans/


    Lars

    #125757

    nightsky
    Deltager
    • Neutron star

    Første farvebillede (RGB) af 67P/Churyumov-Gerasimenk.

    Den er grå, næsten lige så sort som kul. Rødt lys reflekteres en lille smule mere end andre
    farver, da størrelsen af overfladepartiklerne er lille. Iflg. pressemeddelelsen er det noget man
    også ser andre steder i solsystemet.

    RGB billedet afslører også at der ikke er is på overfladen, fordi man ikke ser øget reflektion i
    det blå filter.

    Til info:
    OSIRIS to kameraer
    Narrow – 250 til 1000nm
    Wide – 240 til 720nm

    Super spændende PDF om kameraet, filter .m.m
    http://pdssbn.astro.umd.edu/holdings/ro-a-osiwac-3-ast1-steinsflyby-v1.4/document/osiris_ssr/osiris_ssr.pdf

    Narrow filter opsætning:
    8x Neutral 640 520 Passes only 5% of light (neutral density filter)
    3x NFP-Vis 600 >600 Refocusing lens for near-field imaging
    2x FFP-Vis 600 600 Refocusing lens for near-field imaging
    1x FFP-UV 600 >600 Clear filter for far-field imaging with wheel 2 filters
    x1 FFP-IR 600 >600 Clear filter for far-field imaging with wheel 1 filters
    x5 Far-UV 269.3 53.6 Surface spectral reflectance
    x6 Near-UV 360.0 51.1 Surface spectral reflectance
    x4 Blue 480.7 74.9 Surface spectral reflectance
    x3 Green 535.7 62.4 Surface spectral reflectance
    x2 Orange 649.2 84.5 Surface spectral reflectance
    x7 Hydra 701.2 22.2 Water of hydration band
    x8 Red 743.7 64.1 Surface spectral reflectance
    5x Ortho 805.3 40.5 Orthopyroxene
    4x Near-IR 882.1 65.9 Surface spectral reflectance
    6x Fe2O3 931.9 34.9 Iron-bearing minerals
    7x IR 989.3 38.2 IR surface reflectance

    Wide filter opsætning:
    1x Empty — — Empty position for use with wheel 2
    x1 Empty — — Empty position for use with wheel 1
    3x UV245 246.2 14.1 Continuum surface spectral reflectance
    4x CS 259.0 5.6 CS gas emission
    5x UV295 295.9 10.9 Continuum for OH
    6x OH-WAC 309.7 4.1 OH emission near nucleus
    7x UV325 325.8 10.7 Continuum for OH, surface spectral reflectance
    8x NH 335.9 4.1 NH gas emission
    x3 UV375 375.6 9.8 Continuum for CN, surface spectral reflectance
    x4 CN 388.4 5.2 CN gas emission
    2x Green 537.2 63.7 Dust continuum
    x5 NH2 572.1 11.5 NH2 gas emission
    x6 Na 590.7 4.7 Sodium gas emission
    x8 VIS610 612.6 9.8 Continuum for OI, surface spectral reflectance
    x7 OI 631.6 4.0 O gas emission for dissociation of H2O
    x2 Red 629.8 156.8 Broadband filter for nucleus and asteroid detection
    and redundancy with NAC

    Der er et par filtre jeg kunne ønske mig til teleskopet:
    F.eks. x7 Hydra 701,2 – Ortho 5x 805,3 – x4 CN 388,4 m.fl. man kan sikkert få en del sjov af disse.

    Nightsky2014-12-14 15:30:59


    Lars

    #126140

    Torben Taustrup
    Admin
    • Neutron star

    Seneste billede af 67P – selvom vi er nogle, som ikke er helt enige i APODs valg Wink – dette er så ok.

    http://apod.nasa.gov/apod/ap141223.html


    Torben Taustrup – ttau@tocobs.org – TOC Observatory – http://tocobs.org -12.5″ – f:5 Newt. Starlight XPress SXV H9 og Atik383 CCD-kamera. Fields: 19,6′ x 14,6′ Px: 0,84″ / 39,63 x 29,51 Px. 0,71″ – SkyWatcher 80 mm ED refraktor. TAL Apolar 125 f : 7,5.

    #126142

    edbbob
    • Super Nova

    Hold da op! Det billede er hele turen, de nedbidte negle og alle penge værd!

    #126145

    nightsky
    Deltager
    • Neutron star

    Masser af nyt efter sidste uges AGU konference.

    Pressekonference (1 time)
    [TUBE]ISfa_l-Ji90[/TUBE]

    http://blogs.esa.int/rosetta/2014/12/18/updates-from-agu/

    Desuden er der masser af ballede med OSIRIS science teamet. Tilsyneladende har der
    været massive problemer med instrumentet og af underlige grunde vil man ikke offentliggøre
    de billeder man har. Som de eneste fik de stoppet streaming af billederne fra AUG mødet.
    Åbenbart er der stadig vidensskabsfolk i Europa som mener befolkning (dem der betaler) ikke
    er gode nok til at få data. De gamle dage fra ESA findes stadig.

    Hvis man læser nedenstående kommentar (der er masser af guf), er man ikke i tvivl om at der
    er masser af data som den forstokkede europæiske holdning til offentliggørelse holdes tilbage.
    Der burde indføres samme regler som i USA, fri adgang til da for alle.

    Having seen all the presentations that were actually shown, four are
    still not viewable and
    one was cancelled, I thought I would outline the
    key things that were common conclusions.
    A lot of results just defined
    boundaries or the range of results and some did not match
    existing
    models or experimental data closely enough to give exact conclusions.
    The majority
    of the Philae reports amounted to a list of what data was
    collected and how they might be
    able to use it.

    The Northern “Duckiesphere” currently in Summer is way more active
    than the “Dark Side”.
    The detection of metal ions like Sodium,
    Magnesium, Zinc, Iron is limited to nighttime
    observations and is
    thought to be due to sputtering from the Solar Wind and Cosmic Rays.

    They are not seen during the day, because cometary activity produces a
    coma containing
    gas, ions, charged particles and dust that physically
    and magnetically shields the surface
    from the Solar Wind.

    Activity is directly correlated to the amount of sunlight incident on
    a surface, but the neck
    areas and the north polar plain are more active
    than the head and body lobes due to a
    thinner layer of insulation.
    These more active areas contain fewer organics. The majority of
    the
    surface layer away from the active regions contains between 5 and 7%
    organic
    material, with the highest amounts on the sides of the lobes
    where there is a lot more
    exposed solid material. The nature of the
    organics is still not known, one fit to the data
    suggests a mixture of a
    neutral black material with 99.5% Tholins and 0.5% Water. Another

    result suggests that it is not all Tholins and is likely a mixture of
    Carbon, Tholins, Low Iron
    content silicate minerals and various
    Sulphides.

    The consensus seems to be that in the flatter plains where the
    surface appears to be
    covered in a dust blanket, like at the first
    touchdown point, there is a top ice free layer of
    friable, porous,
    gravel and dust about 1cm thick made up of low iron minerals, silicates,

    organics and Carbon. Below that the material starts to contain volatile
    ices, the amount
    increasing with depth. This mixed ice/dust/organics
    layer varies, but is estimated to be 10
    to 20cm normally, but may vary.
    Beneath this is a hard layer of sintered ice/dust/organics,
    which
    although hard is also brittle as evidenced by the shards seen in the
    ROLIS images.

    Sulphur is present in significant amounts and is usually found in the
    areas where Water is
    coming from, but also from a few areas where very
    little Water is seen. Although visually
    the comet is pretty homogeneous,
    chemically it seems not. Water tends to be produced in
    very variable
    amounts related to the time of day and position on the comet, whereas

    Carbon Dioxide emission seems to be more constant. The ratio of CO2/H2O
    is on average
    about 7%. The thermal properties of the top dust layer
    suggest up until now outgassing is
    not coming from the harder sub
    surface layer.

    The CONSERT talk was limited and the second one cancelled, presumably
    because Philae
    has not been located. The data is clear and of good
    quality, but the only conclusion is that
    the shape of the signal peak
    indicates very little or no scattering from internal surfaces,
    meaning
    the comet is not currently made up of metre or two sized planetesimals,
    but is a
    continuous solid.

    Organics that have been identified include C2, C3, C4 compounds and
    Benzene. Other
    results indicate Amines, Benzoic Acids, Ketones and
    Esters are probably present as well.
    Dust particles from the comet are
    larger than expected, but are very irregular,
    conglomerates of very
    loosely bound material which falls apart on contact. More solid grains

    have been examined which although only micron size look like mini
    comets, with planes,
    pits and holes. They have also been seen to move
    once trapped in the instrument. This
    was explained as being their light
    weight, but sublimating gas creating a frictionless layer
    underneath
    them likely helps.

    The surface layer at Agilkia was revealed in all it glory by the
    ROLIS images. Hopefully those
    images will be available here soon. This
    was the most informative and revealing
    presentation shown. Analysis was
    done of the particle sizes and the surface seems to be
    made of a sort
    of pea gravel 1 or 2 cm in size with larger pieces of broken cryorock
    mixed
    in. Hollows and depressions around a metre in size along with
    small ledges and elevation
    changes in the 10s of cm range. Little tiny
    landslides of little pebbles, but little sign of dust
    except at the base
    of the 5m Cryobolder close to the touchdown point. It would appear
    that
    the surface layer material is very much like a type of aerogel, it
    holds it shape perfectly
    until disturbed and then just disintegrates
    into a fine powder. This is what was seen in
    both MIDAS and COSIMA.
    Unfortunately the dust measuring device on Philae has so far only

    registered 1 confirmed hit.

    The team seem even more confident that Philae will survive and be
    able to do more
    science. It is clear from these presentations that there
    is lots of revealing data available,
    there are vast amounts of it and
    much of it requires some new algorithms and models to
    interpret,
    especially the Philae data. An amazing job by everyone involved. I
    should also
    add that the speakers were way more entertaining and
    interesting than many of the
    others here.

    So most of what we learned in the presentations that were shown, had
    already been
    deduced by ourselves or explained by team members here and
    this just added confirmation
    that many peoples combined educated guesses
    were right. The talks showing OSIRIS data
    and explanations of the comet
    morphology were not streamed and information from the
    plasma and
    magnetic field experiments were not shown. Hopefully some sort of
    apology or
    explanation from the ESA team will be forthcoming to explain
    this.


    Philae’s view of “Perihelion Cliff” at its final resting place on the comet’s surface. Credits: ESA/Rosetta/Philae/CIVA

    Og denne film Comet Watch

    Nightsky2014-12-23 19:06:20


    Lars

    #126151

    jens.jacobsen
    Deltager
    • Super Nova

    Hejsa.

    Inspirerende lille film, med den tumlende komet.

    Det fik mig til at tjekke hvornår kometen igen ville være tilgængelig på vores nathimmel, og det viser sig at i januar-februar 2016 vil det være muligt at lave en lyskurve på kometen. Derved kan vi jo selv se om kometen stadig tumler på samme måde. Der skal nok en pæn kikkert, f.eks en 12″ eller mere til, da kometen er mag 14 på pågældende tidspunkt.

    Nogen frivillige??

    mvh
    Jens

    #134091

    lindhard
    Deltager
    • Super Nova

    Dsværre kniber det tilsyneladende med at vække Philae af frostdvalen selv om Sollyset nu er 10x stærkere end ved landingen.

    LinkLindhard2015-06-13 20:14:42


    mvh
    Lars

    #134103

    norup
    Deltager
    • Super Giant
    #134104

    Torben Taustrup
    Admin
    • Neutron star

    YES! Thumbs%20Up
    Nu bliver det spændende at se, hvordan den vender – og om de kan lokalisere den.


    Torben Taustrup – ttau@tocobs.org – TOC Observatory – http://tocobs.org -12.5″ – f:5 Newt. Starlight XPress SXV H9 og Atik383 CCD-kamera. Fields: 19,6′ x 14,6′ Px: 0,84″ / 39,63 x 29,51 Px. 0,71″ – SkyWatcher 80 mm ED refraktor. TAL Apolar 125 f : 7,5.

    #134106

    nightsky
    Deltager
    • Neutron star

    “Philae is doing very well: It has an operating temperature of -35ºC and
    has 24 Watts
    available,” explains DLR Philae Project Manager Dr.
    Stephan Ulamec. “The lander is ready
    for operations.”

    Sikke en god nyhed.

    http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_lander_Philae_wakes_up_from_hibernation

    http://www.independent.co.uk/news/science/rosetta-mission-philae-comet-lander-wakes-and-contacts-earth-10318822.html


    Lars

    #134107

    Torben Taustrup
    Admin
    • Neutron star

    “Philae phone home” Wink


    Torben Taustrup – ttau@tocobs.org – TOC Observatory – http://tocobs.org -12.5″ – f:5 Newt. Starlight XPress SXV H9 og Atik383 CCD-kamera. Fields: 19,6′ x 14,6′ Px: 0,84″ / 39,63 x 29,51 Px. 0,71″ – SkyWatcher 80 mm ED refraktor. TAL Apolar 125 f : 7,5.

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