New Iapetian image series |
New Iapetian image series |
Sep 11 2006, 09:27 PM
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#1
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Member Group: Members Posts: 288 Joined: 28-September 05 From: Orion arm Member No.: 516 |
Hi,
CASSINI has transmitted 184 pics (!) over the last days. Here five takeouts, 3-4x enlargement: Date: 2009-09-06 Distance: 2.228.548 km Filters: CL1 and CL2 Date: 2009-09-08 Distance: 3.215.284 km Filters: P120 and GRN Date: 2009-09-08 Distance: 3.216.610 km Filters: P60 and GRN Date: 2009-09-09 Distance: 3.390.271km Filters: P60 and GRN Date: 2009-09-09 Distance: 3.427.313 km Filters: P120 and GRN Maybe somebody is able to combine some of those images to show more details. Bye. |
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Feb 14 2007, 11:25 PM
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#2
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Huh...that "yin-yang" aspect makes Iapetus look like one of the hemispherical views of Fritz Leiber's The Wanderer...art imitating life in yet another subtle way, albeit decades in advance.
Just struck me also how deep & pronounced all these craters are in comparison to those on the inner large icy moons. Is this difference perhaps due to fallout from Enceladus on the latter, as discussed on another thread, or are we seeing evidence of a thicker crust on Iapetus? -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 15 2007, 04:24 AM
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#3
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
or are we seeing evidence of a thicker crust on Iapetus? To extend this discussion, consider Iapetus accreting from the primordial chaos. Iapetus (or more accurately, the proto-Iapetus) pokes along in its' orbit at 5000 KPH (or was it MPH? no matter) and takes ~80 days to loop around Saturn. Its' accretion process took much longer than any other 'big time' satellite in the solar system. During this longer coalescense, the Al27 in the incoming materials had longer to radiate its' heat to space, and Iapetus had longer to radiate the collisional heating from impacts that formed it. Iapetus will be the satellite most accurately we can describe as cold formed. The crust will have enormous bearing strength. As we saw in the Cassini pix, the lumpy, facety surface of Iapetus exists to this day. The 'cat scratch' feature (IIRC, SW of 'landslide crater') might record an extremely deep penetration into the solid body of Iapetus by the impactor that made the 'landslide basin'. Assuming a formation via external agency of the equatorial ridge structure long after Iapetus accreted, the structure rests on the surface, is 20 km high (60,000+ feet high!!!), and to date, in the Cassini photos, we see no faulting parallel to the ridge. Additionally, to date, we see no signs of volcanism, past or present, no geysers, plumes, mud pots or warm spots. Internal heat sources have been inoperative at 'softening' the crust for a very long time. Something else reducing the heating to the interior of Iapetus ids it's distance from Saturn. Granted, Iapetus is tide locked to Saturn today, but of all the major satellites in the solar system, tidal braking of Iapetus was uniquely slow. Any power dissipated this way had ample time to radiate away in the cryogenic environment, to no or little effect. |
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