CometWatch – 10 August

Rosetta navigation camera (NAVCAM) image taken on 10 August 2014 at about 110 km from comet 67P/C-G. The phase angle is about 45 degrees.

View and download image here.

Full-frame NAVCAM image taken on 10 August 2014 from a distance of about 110 km from comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

Full-frame NAVCAM image taken on 10 August 2014 from a distance of about 110 km from comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM



  • Ingo Althöfer says:

    Another interesting shot with a new angle
    of illumination. Thanks for sharing.


  • J says:

    How would 67P look to an astronaut travelling with Rosetta?
    (i.e. to the naked eye without contrast enhancements etc.)
    Or would it just be a black blob against a starry-backdrop

    • Solon says:

      Likely not visible to the eye. The NavCam is a Star Tracker, which can only be used on very dim objects. As no stars are evident in any of the images, the exposure time would seem to have been very short, but that still does not mean that the object would be naked eye visible, as the instrument may be imaging in UV or IR. How the Star Trackers work is still classified information.

  • raymundo dionicio says:

    I’m intrigued
    at the chemistry
    showing at the vertices
    bordering sublimation craters.

  • raymundo dionicio says:

    I had never before
    tough of the sun
    as an sculptor


  • Mark S says:

    Is the dark spot on the body a dark-pixel-artifact caused by NAVCAM as it’s been mentioned on another picture some day’s ago?
    How long will it take to acquire pictures that exceeds the actuall resolution limit?


  • John Smykla says:

    Nice! It looks so peaceful when away from the Sun, can’t wait to see the landding.

  • Marc says:

    This is amazing

  • Is there a preferred orientation in which one should present NavCam and OSIRIS images in popular articles? The PI of the latter camera told me today that there is no agreed-upon coordinate system yet, but we know the rotation axis: should ‘north’ be up?

  • Sajid Rabbani says:

    It gives me so much inspiration to know that this machine could go as far as some 3 billion miles away from earth and still under control. Just excellent.

    • emily says:

      Hi Sajid – just to clarify – the furthest Rosetta travelled away from Earth was about 937 million kilometres (and the furthest from the Sun was 880 million kilometres, close to Jupiter’s orbit — in fact, Rosetta was the first spacecraft to fly close to Jupiter’s orbit using only solar cells as its main power source!) And over the last ten years the spacecraft has travelled a total of some 6.4 billion kilometres, thanks to its journey through the Solar System that took it around the Sun five times to complete flybys at Earth (three times) and Mars (once)… all of which is indeed an excellent achievement 🙂

  • aaron wenger says:

    Interesting to me how “melted” surface appears. Long ago I helped to develop a model of cometary nucleus which was built around the formation of gas hydrates. As the low temp form of these were slowly modified by shining intense visible light onto the surface a ablated structure similar to this was seen. A short period comet such as this one would have been in a relatively strong light environment for several billion years now. I bet the surface is depleted gas hydrate ices and left behind hydrocarbons.

  • Ckive Hartland says:

    Another aspect showing the erosion of the comets surface. A question, does the Solar radiation put a drag on the comet?
    Does this then align the comet in the direction of solar flow?
    The larger mass of the comet then being turned away from the solar rays so that the smaller mass faces the rays, then surface erosion would match this picture.


    • Daavs says:

      Even a low-density, small celestial body such as this comet still has a very low area-to-mass ratio compared to a spacecraft, meaning that the effect of solar radiation is extremely small.

      We already know that the comet is not aligned with the direction of the sun because of it’s spin period of 12 hours. If it were aligned, the shadows in the various images would look the same every time. But if you’d like to know how solar pressure affects the orbits and spins of small bodies, look up the Yarkovsky effect and the YORP effect on Wikipedia. These may be more relevant for asteroids than for comets though, since the comets’ outgassing of volatile materials is a complicating factor.

  • Cordell says:

    How sad that I only live in the era that is on the cusp of such fantastic science, engineering and space technology along with everything else that leads to our future amongst the stars (disregarding the fact that we always live in an ear relative to our time).

    We’re witnessing the infancy of so many things to come. I look at these fantastic photos of Comet 67/P/C-G and would have loved to be a part of the engineering team in getting us to this stage and the mission’s planned full lifecycle.

    And again as I look at these photos I would love to be a geologist that understand the formations, textures, fluidity and the sheer complexity and shape of the comet along with its indents, craters and in some instances it’s baffling geometric features.

    I so hope that from this awareness of our inevitable future amongst the stars that more and more of our young are inspired to take the baton of this greatness.

    I recall feeling like this while watching live coverage of Neil Armstrong set foot on the moon and the Apollo 13’s hazardous and successful return trip, and again when the shuttle lifted off on its first mission to the ISS.

    Regardless of current world status……….aren’t we a great species with such phenomenal potential.

    In the words of the famous Buzz Lightyear of Star Command: “To Infinity and Beyond”

  • Prise de vue fantastique !!!!

  • Dave Higgins says:

    Great picture Emily, but when we were promised a picture a day, we thought they would be ever closer, please can you puts something on thats a bit closer. I appreciate that the orbit or Rosetta is a bit odd at the moment, but even so.

    • emily says:

      Hi Dave, the spacecraft is at approx. 100 km (+/- a few km) for the first half of August, so we can’t show anything closer just yet, because we simply aren’t any closer. If you check the animation that shows the trajectory ( then you’ll see that we start to progress to an altitude of 50 km towards the end of the month, and then closer still in September and October.

  • Sajid Rabbani says:

    Thanks Emily

  • I’m so impressed with the Rosetta mission. Good work and please keep bringing us these incredible images!

Comments are closed.