New Iapetian image series |
New Iapetian image series |
Feb 16 2007, 08:50 PM
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#46
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Member Group: Members Posts: 288 Joined: 28-September 05 From: Orion arm Member No.: 516 |
Hi,
I've just checked the JPL raw images page for new iapetean pics - and was successful: 189 new images between Feb.12th and 16th (!) Looks like there has been a shadow casting show by saturn during this time on Iapetus... Here some takeouts: Date: 2007-02-13 Distance: 2.269.440 km Filters: CL1 and CL2 4x enlarged Date: 2007-02-13 Distance: 2.267.233 km Filters: CL1 and CL2 4x enlarged Date: 2007-02-13 Distance: 2.264.177 km Filters: CL1 and CL2 4x enlarged Date: 2007-02-14 Distance: 2.248.671 km Filters: CL1 and GRN 4x enlarged Date: 2007-02-14 Distance: 2.248.666 km Filters: CL1 and CL2 4x enlarged Date: 2007-02-14 Distance: 2.248.655 km Filters: CL1 and UV3 4x enlarged Date: 2007-02-15 Distance: 2.322.227 km Filters: P120 and MT2 4x enlarged Have a view at the whole images series and you will recognize a migrating shadow on Feb.13/14th, maybe somebody can affim an iapetean eclipse using some simulation program?! Bye. |
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Feb 16 2007, 09:27 PM
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#47
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Senior Member Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
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Feb 16 2007, 09:35 PM
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#48
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
No way! Mega cool!
Stretched color snapshots at the start and near maximum eclipse: So... Saturn really is yellow. Who would have known! -------------------- |
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Feb 16 2007, 10:20 PM
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#49
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Way nifty. Here's an animation of the February 14 set, magnified 2x. Note that since this is during an eclipse, the ones that aren't in eclipse are necessarily pretty much zero phase.
Those of you who've worked more with making the raw JPEGs pretty, can you suggest improvements? --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Feb 16 2007, 10:25 PM
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#50
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
Actually, not necessarily zero phase. Remember this isn't the case where the observer is located on the body that's casting the shadow. I get a 14.5 degree phase from Cassini's vantage point at Feb 14, 02:00 UTC
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Feb 16 2007, 10:31 PM
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#51
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Oops! Thanks for the correction. Glad I got it here before I posted the wrong thing in the blog
--Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Feb 17 2007, 02:28 PM
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#52
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Member Group: Members Posts: 509 Joined: 2-July 05 From: Calgary, Alberta Member No.: 426 |
I noticed the "darkened" images of Iapetus and wondered what had caused that -- it never even occurred to me that it might be Saturn's shadow. Neat.
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Feb 18 2007, 03:47 PM
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#53
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Member Group: Members Posts: 288 Joined: 28-September 05 From: Orion arm Member No.: 516 |
Btw, I once (2006-03-14) posted this:
QUOTE And some pre-info about upcoming encounters: 2006 Mar 25 to Apr 18: Apr 11 - 602.412 km; 14-3.6 km/pxl; medium to high phase, southern hemisphere as crescent 2006 Jun 17 to 27: Jun 23 - 1.343.000 km; 14-8.1 km/pxl; medium to low phase, sub-Saturn hemisphere 2006 Sep 08 to 09: Sep 02 - 1.816.000 km; ~20 km/pxl; zero phase (3 to 0.05 deg), sub-Saturn 2006 Nov 26: 1.997.000 km; 12 km/pxl; very low phase, sub-Saturn 2007 Feb 12 to 15: Feb 14 - 2.249.000 km; ~14 km/pxl; sub-Saturn; very low phase and eclipse 2007 Apr 14: 2.256.000 km 2007 Jun 22: 1.817.000 km; ~14 km/pxl; med. phase, trailing side 2007 Sep 03 to 09: 8.6-0.7 km/pxl; very high phase, western Cassini Regio 2007 Sep 10: 480-10-540 m/pxl; targeted flyby, trailing side 2007 Sep 11 to 17: 0.7-7.1 km/pxl; low phase (~33 deg) trailing side 2007 Sep 27: 15 km/pxl, low phase sub-Saturn+trailing side 2007 Nov 26: 1.371.000 km; 8.2 km/pxl; very high phase, north pole, possibly graylight 2008 Feb 13: 2.045.000 km; 14 km/pxl; high phase, north pole, possibly graylight Didn't realize the event of an eclipse at that time! Bye. |
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Feb 18 2007, 07:31 PM
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#54
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
Interesting . . .
Iapetus traversing the Saturnian shadow and the Saturnian magnetotail. Effluvia wafted from the Titanian atmosphere possibly lofting into Iapetus' space . . . . |
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Feb 19 2007, 12:04 AM
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#55
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
This is probably an FAQ for the unhip (and please feel free to slap me if needed!), but will Cassini get any really good views of the dark/light border areas this September? Seems as if that's key for determining the origin of the Great Dark Splat...
-------------------- 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 19 2007, 12:09 AM
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#56
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Member Group: Members Posts: 509 Joined: 2-July 05 From: Calgary, Alberta Member No.: 426 |
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Feb 19 2007, 12:48 PM
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#57
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Member Group: Members Posts: 288 Joined: 28-September 05 From: Orion arm Member No.: 516 |
... but will Cassini get any really good views of the dark/light border areas this September? Seems as if that's key for determining the origin of the Great Dark Splat... We'll get a fairly good view of the most interesting 'White mountains' or 'Voyager mountains' at the western border of Cassini Regio to Roncevaux Terra... CASSINI will follow the equatorial ridge from east to west first looking at a cresent Iapetus. Btw, there will be two far encounters before: April 15th July 5th Both will show some parts of the terra incognita including a huge bassin about 400-500 km in diameter... Bye. |
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Feb 19 2007, 03:30 PM
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#58
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Thanks, TA & Rob.
Main thing is that we need to examine the border region with as much high-res as possible. The outer edges of the deposit should provide some clues on exactly how this stuff was laid down. Abrupt or very gradual borders could indicate a radiational origin as Tasp suggests, while streaky, irregular borders would suggest either an eruptive origin or infall from somewhere else. -------------------- 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 19 2007, 03:38 PM
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#59
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
We might note a correlation between degree of darkening, altitude, and longitude in the light/dark coverage.
Seems like a mathematical model or simulation analyzing sun exposure (insolation), local slope, altitude, longitude, and the Iapetan parameters of ~80 day long 'days' and introduction of a gaseous discoloring agent at aphelion could be made. Program needs to be recursive, the darkening modifies the local temperature and facilitates further darkening. Interesting if someone comes up with some random topology to run through the program to see if it generates Cassini Regio like stains on the object. |
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Feb 19 2007, 03:41 PM
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#60
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
Or tackling the problem the other way round, someone (more capable with math than I) confirms images of Cassini Regio darkening does correlate with altitude, local slope, longitude, and insolation . . .
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