CometWatch – 4 August

Rosetta navigation camera (NAVCAM) image taken on 4 August 2014 at about 234 km from comet 67P/C-G.

As you can see, the comet is not centred in the full-frame image. This is a result of the rendezvous burn conducted the previous day, which adjusted Rosetta’s trajectory towards the comet. This effect is corrected for in the commands sent to the spacecraft after the new orbit has been determined.

The window size for today’s sub-image is 400 x 400 pixels and the factor for scaling up and interpolation is 2 (like yesterday). 

From tomorrow the nucleus should be large enough to provide the full-frame image only!

Full-frame NAVCAM image taken on 4 August 2014 from a distance of about 234 km from comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

Full-frame NAVCAM image taken on 4 August 2014 from a distance of about 234 km from comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

View and download interpolated image here.

Crop from the 4 August processed image of comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

Crop from the 4 August processed image of comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM



  • Andrew R Brown. says:

    Astonisihing image.

    Looks like that ‘smoother’ area has some ice boulders and / or icy outcrops.

    Looking like a potential Philae landing site although high resolution OSIRIS NAC imagery will be required for sure.

    Many features look like ablation features, even though comet67P/Churyumov-Gerasimenko has only been in an orbit to allow sublimation only very recently, so could be impact features that have frozen.


  • Fabio Miguez says:

    Almost there! It’s so exciting to see so much science about to be gathered and refined!

    As a note, although you already have a video on it, I’d be interested to know why the three-arches approach was selected as the initial trajectory around this comet.

    Thanks for a great blog and frequent updates, you guys rock!

    • Kevin says:

      Simple answer on the triangle orbit, as noted elsewhere on this site. Without precise knowledge of the mass and center of gravity of the comet, you can’t go into a direct orbit. That comes partly from the triangle approach.

  • Piot says:


  • Chr says:

    Why isn’t this comet called Twitter? Seems like all images are stowed away over there instead of on

  • Simon Frederik says:

    Simon : Just a hint , if there is dust and ice orbiting the comet (also due to the rise in activity of the comet earlier this year) and what can be hazardous for Rosetta , it will probably be more abundant in the ecuatorial plane of the comet .
    Good luck these crucial days !!

  • raymundo dionicio says:

    Just my mind
    or is some hexagon-icity
    evident on the biggest

    Also the biggest ones
    look too much similar size.
    Those doesn’t look like
    impacted, must be sublimated

  • raymundo dionicio says:

    It’s going to be
    a hell of a weather
    at such a close range!


  • Raoul says:

    I see round, impact crater like shapes. But they seem to be higher in stead of deeper than the rest.
    Is it possible that impacts have compacted comet material, making it slower to evaporate near the sun than the area without impacts? Which then evaporates, leaving crater-shaped higher rock sticking out?

    • It is possible that craters, which would fracture and melt ice which would then re-freeze, are more resistant to subsequent erosion than the undisturbed surface. This would leave them as topographic highs after a few passages near the Sun; such things have been observed on Mars with old streambeds, which now may be raised features.

  • Clive Hartland says:

    I would think that the erupted shape/configuration on the surface would be from the heating up as the comet goes near the Sun, then as it cools the ‘Form’ of eruption is cooled and shows as it does now.
    I also think the surface may become quite violent as it is heated by the Sun and the bits fly about. This we will have to wait and see later.


  • Ravi Agnihotri says:

    It’s just awesome . Salute to science.

  • Crazee says:

    Is there a slight chance that a 3D-Model will be published?

  • CMariotte says:

    The less spherical, the more solid… can we say that ?

  • Stephan Andersohn says:

    From my point of view it’s like a rosty onion. There are maybe a lot of layers of ice and other darker particle and if the sun heats up they separate. We will see what Rosetta will tell us.

  • dariusz says:

    Will Rosetta affect comet’s trajectory in some minimal way?It has it’s own gravitational pull.

  • morganism says:

    Thanks again ESA and German camera team for releasing these fab images so quickly.

    Lots of excitement on the interwebs in the space enthusiasts sites, and you havn’t even done your major media splash yet.

    If only i could see the reCaptcha….

  • Matt Revenaugh says:

    What kind of structure can be holding the two halves together? Wouldn’t centripetal forces prevail?

    • fathers4justice says:

      it is just gravity and might be even now almost an euqilibrum from centripedal and gravity dependent from turning rotation and the gap is filled up more and more with what comes near – over the time in the long run!

  • frankebe says:

    I’m still going with NO ice, just rock.

  • Joaquin says:

    Felicitaciones a todos los que hacen posible la supremasìa de la Ciencia. Adelante Rosetta!!!

  • Paul says:

    Magnificient ! One large step for science, and a small one for humanity. Remind us how small our planet is and how much time it might take human kind to travel to outer planets, thinking of Voyager 1 and 2 here.
    Keep the good work !

  • Mike H says:

    Solid rock. Hope they have alternatives to the snow harpoon and ice screws on board for mooring… :\

  • Frank says:

    That must me some huge work of calculation! Would like to have an explanation, summayr on how it’s been done?

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