A science blog with Eric Berger





The comet tumbles (European Space Agency GIF)

Click to see the comet tumbling (European Space Agency GIF)




Categories: Astronomy, National, Space
Eric Berger

21 Responses

  1. Bill in Houston says:

    Oh look, I can see my house from here!

  2. bg says:

    that’s seriously cool.

  3. John says:

    That is so cool. Good luck on the rest of the mission.

  4. Mike says:

    Is that a comet or a meteor? How big is it?

    • Keith says:

      It is a comet. Meteors are small bits of rock that strike the earths atmosphere. This comet is mostly water ice and dust. Don’t know for sure but it is probably 10-15 miles on its long axis.

    • JohnD says:

      67P/Churyumov–Gerasimenko is a comet; it was discovered by Klim Ivanovych Churyumov on a photographic plate taken by Svetlana Ivanovna Gerasimenko. Right now, it has a period of 6.45 years thanks to an encounter with Jupiter back in 1959 that altered its previous, much larger orbit. (This is why folks who assume that NEOs are all more than 10,000 years old are full of it; this sort of thing happens more often than you might think.)

      As the comet outgasses, it does spray dust and small rocks into space around it. If any of those were to hit the Earth’s atmosphere, then they would become a meteor.

    • JohnD says:


      That’s a little optimistic. The comet is roughly 3 km x 5 km (2 mi x 3 mi) and consists of two large blobs of ice stuck together (what wonks refer to as a “contact binary nucleus”). For reference, Chicxulub was about 10 km (6 mi) across.

      If you put the comet down in Memorial park, it would cover the entire area and have one bit that stuck out almost all the way to Heights Blvd.

  5. bkbirge says:

    Stunning photos, especially that gif animation.

  6. Ken says:

    GoPro HD?

  7. Mike Corey says:

    Fly me to the moon
    Let me play among the stars
    Let me see what spring is like
    On a, Jupiter and Mars

  8. JJ says:

    Looks like Q-Bert in the first pic, lol

  9. hunter says:

    So cool. How as it held together, and how long has it done so? Its shape looks like it would fly apart under even slight tidal stresses that would exist in a close fly-by of the sun or outer planets.
    This was a great choice for a comet to explore.

    • JohnD says:

      Well, we know that it has already had at least one close encounter with Jupiter back in 1959; that was what changed the orbit from a millennial one to one taking just 6.45 years.

      It appears to be the remains of two larger bodies that collided early on in the Solar System’s history and which have been slowly sublimating away ever since. It was selected in much the same way that Tempel 1 and Wild 2 were – it would be in the right place at the right time for Rosetta to rendezvous. Given the large number of such objects in the Solar System, it was just a matter of sifting through the candidates until a suitable one was found.

  10. Jack says:

    Water, ice and dust that looks like a giant rock.
    How can that be described as “stunning”
    The stunning part is how the spacecraft Rosetta caught the Comet at all.

  11. Lab work from this hand sample leads me to believe that in fact comets are composed of high temperature crystalline silicates. Small mm sized and sub-mm near circular grains welded together with carbon and iron compounds under extreme high pressure. While our sample has yielded some monochromatic gases we believe water-ice (as we know it) has no place in actual comets. I have long been wanting to change our web page to reflect these findings but I have been too lazy to do it. I should be excused for it becasue the work was overwhelming for essentially one person being undermined by NASA plants.

    S. Ray DeRusse.

  12. Jack says:

    Considering the European Space Agency probably spent a ton of money on this mission and it took 10 years to finally happen, it seems during that time someone could have come up with a really cool name for the Comet instead of that dull scientific term 67P.

    • Eric Berger says:

      The comet has a name. But it’s a mouthful: Churyumov-Gerasimenko.

      So 67P is a nice shorthand.

    • PDQPete says:

      And two men the world praises
      And two men the world blames:
      And messrs. Churyomov-Gerasimenko are their names–HOI!

    • Tom Lehrer says:

      Will you ever forget the day PDQPete met those two men?
      In one pic they showed him the secret to success in astronomy
      That’s what time lapse is for!
      Look at now and before,
      With a blink comparator -
      Only please to be calling it “animated gif”.