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Cassini Shows Close Up of Iapetus

Posted by michael on from the looks-rocky dept.

dazza101 writes "The Cassini spacecraft passed within 72,000 kms of the Saturn moon Iapetus yesterday, taking a series of spectacular images of this intriguing moons rugged surface. An excellent prelude to what promises to be one of the major stories of the new year, the plunge of the Huygens probe into Titan's atmosphere on January 24."

22 of 156 comments (clear)

  1. If that's no space station, what is it? by IO+ERROR · · Score: 4, Funny
    Iapetus doesn't concern me. What concerns me is Mimas, which has a clearly visible crater with a mountain inside it.

    I have a hard time believing that's a natural formation. And I'm concerned that whatever did it might still be bouncing around the universe somewhere.

    Anyone have any idea what could have caused a formation like that?

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    1. Re:If that's no space station, what is it? by Pinkfud · · Score: 5, Informative

      That's a "rebound effect". Whatever caused that crater was so big and hit so hard that it penetrated the moon's crust. The more plastic inner material was violently compressed, then shot out through the center of the crater forming the "mountain". It's a rare phenomenon, but I don't have any trouble believing it's natural.

      --
      The world is my oyster. That's why it's always in a stew.
    2. Re:If that's no space station, what is it? by dn15 · · Score: 3, Insightful
      And I'm concerned that whatever did it might still be bouncing around the universe somewhere.
      Even if it is, does it matter? I don't see how this would be any greater cause for concern than the objects that made other huge craters on other planets/moons/etc. I mean, respectfully, it's not news that there are big things floating out in space, or that some of them have collided with other objects. And if it does head our way, I have faith in Bruce Willis.
    3. Re:If that's no space station, what is it? by Anonymous Coward · · Score: 3, Informative

      Large impact craters are characterized by central peaks. This type of crater ("complex impact crater") is common on the Moon, Mars, Earth, and all other bodies with impact craters. The peak forms by rebound of the crust. This page has some details: http://www.solarviews.com/eng/tercrate.htm

    4. Re:If that's no space station, what is it? by Turing+Machine · · Score: 4, Informative

      You can see a similar phenomenon in these high speed photos of water droplets.

    5. Re:If that's no space station, what is it? by Squid · · Score: 3, Informative

      Here's a crater on the Moon with such a peak. I guess it really gets around.

      They're called rebound peaks and they are a common feature of impact craters, and perfectly natural.

      --
      ~ radiographite: art by john shepard
    6. Re:If that's no space station, what is it? by The+Journalist · · Score: 5, Funny

      Cheney should be very worried now. NASA's found his prototype Death Star.

    7. Re:If that's no space station, what is it? by pediddle · · Score: 3, Informative

      If by "more accurate detail" you read exaggerated artificial relief done with Photoshop, then by all means, check out the photo.

    8. Re:If that's no space station, what is it? by Angry+Toad · · Score: 3, Interesting

      Another feature I'm quite curious about is this globe-spanning ridge. I haven't seen any mention of it anywhere yet.

      It seems (though I may be wrong) to sit dead-center on the darkened portion of the moon and span much of the length of the dark part as well. Is there a connection perhaps? I'd be interested in the opinions of any planetary astronomers.

  2. Cassini Hyugens by metlin · · Score: 3, Funny

    Cassini Hyugens sounds like the name of a Scandinavian supermodel or something.

    And here I was hoping for some spectacular pictures :-(

    What do I see? Big round thing with holes. Different, but not the way I imagined :-/

  3. There are.... by deglr6328 · · Score: 4, Informative

    ....also many more images if you go straight to the raw feed.

    --
    - "Hear that?! The percolations are imminent! Cease your ingress!"
    1. Re:There are.... by deglr6328 · · Score: 4, Informative

      I think you were replying to the AC next to me but I'll reply anyway! :o) It's not a UFO and it's not a star and it's not a comet or planet. Its a proton, or perhaps, an electron. Accelerated to relativistic velocities by the soalr wind or saturn's magnetosphere (or both) it struck the cameras CCD at an angle and as it traveleld through, excited some electrons in the valence band of the semiconducting image detection layer to the conduction band, just like a photon of visible light would if it hit the detector and produced a streak in the image. It's called a "cosmic ray hit" and there is software to remove them from the images.

      --
      - "Hear that?! The percolations are imminent! Cease your ingress!"
  4. Not fair, not square. by Pig+Hogger · · Score: 4, Funny
    Something's missing, like big, square, black thin block.

    (No, you won't get it if you didn't read the book).

  5. Bah... by el-spectre · · Score: 4, Funny

    Call me when they find a monolith...

    --
    "Faith: Belief without evidence in what is told by one who speaks without knowledge, of things without parallel." - A.B.
  6. Wrong date. by daquake · · Score: 4, Informative

    The Huygens plunge is January 14'th, not the 24'th :) 2 Weeks is hard enough to wait for! :)

    --
    Be True, Unbeliever
  7. Arthur C. Clarke and Iapetus. by NarrMaster · · Score: 3, Interesting

    In 2001: A Space Odyssey, Clarke described Iapetus as having a black circle painted on it, with a white circle within.

    When one of the Voyager probes photographed Iapetus, a "circular" black area was found with a smaller white area within.

    Why is this interesting? 2001 was published in 1968. The Voyager probes didn't visit Jupiter until 1980 (V1) and 1981 (V2).

    --
    That's right. All your base.
    1. Re:Arthur C. Clarke and Iapetus. by deglr6328 · · Score: 3, Interesting

      Carl Sagan, who was on the Voyager imaging
      team, sent him a JPL photo (he was a member on the voyager team) with a note scribbled on the back. it said: "Thinking of you"....

      --
      - "Hear that?! The percolations are imminent! Cease your ingress!"
  8. Re:WRONG DATE !!! Huygens descends on the 14th. by eclectro · · Score: 4, Funny


    Actually submitter is right.

    The probe does descend into the atmosphere on Jan 14th, but it takes an additional 10 days to photoshop the results.

    --
    Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
  9. Re:Nasa needs better cameras. by sacredchao · · Score: 3, Informative

    Also, resolution ain't everything. You can bet that this camera, like the mars landers and unlike your generic handheld digi-camera has a CCD an inch or two wide rather than a few millimetres. Good light sensitivity makes up for a lot. Big chunky pixels in the CCD mean fewer dead black spots from radiation and suchlike as well.

  10. Re:All these missions seem to end... by snake_dad · · Score: 4, Informative
    At the risk of trollbating... Missions like Pioneer 10/11 and Voyager 1/2 were fly-by missions. They were accelerated to tremendous speeds by one or several gravity assists, and thus merrily went their way out of the solar system. More recent missions are designed to enter orbit around the targeted planet, and to achieve orbit they have to slow down a lot. It would cost a huge amount of fuel to get them going again fast enough to exit the solar system, and all that fuel would have a big impact on how much instruments could be carried along.

    Some missions (like Galileo) were indeed crashed onto the target planet to prevent them becoming a problem later, or to use the impact as a science data point. Other missions were crashed quite unintentionally.

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  11. Re:Iapetus by Guppy06 · · Score: 3, Funny

    "Why do we name everything using greek mythology?"

    Because Galileo got frist p0st.

  12. Re:Iapetus Ring by Tablizer · · Score: 3, Informative

    I've noticed in a lot of the images, there appears to be a ring of mountains around most of Iapetus's equator: Here, here and here....I'm no scientest, but is it possible that this moon once had a ring system like Saturn itself? Over time the ring particles fell out of orbit and formed the mountains along the equator.

    The "ring of mountains" is indeed pretty darn odd. Never seen it on any other moon that I know of, at least not one that extends that far around.

    But, I doubt falling ring debri would cause such. The material in Saturn's rings does not add up to much if collected in one spot, for example. My speculation is that it is a shock fault caused by a huge meteor impact. However, these usually end up on the opposite side, not around the middle. Whatever it is, I bet a bunch of planetary scientists are happily scratching their heads for answers.

    And I thought the "icy" moons would prove boring. I was wrong.

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