IPB

Welcome Guest ( Log In | Register )

12 Pages V  « < 2 3 4 5 6 > »   
Reply to this topicStart new topic
New Iapetian image series
TritonAntares
post Feb 16 2007, 08:50 PM
Post #46


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... wink.gif

Here some takeouts:
Attached Image

Date: 2007-02-13
Distance: 2.269.440 km
Filters: CL1 and CL2
4x enlarged

Attached Image

Date: 2007-02-13
Distance: 2.267.233 km
Filters: CL1 and CL2
4x enlarged

Attached Image

Date: 2007-02-13
Distance: 2.264.177 km
Filters: CL1 and CL2
4x enlarged

Attached Image

Date: 2007-02-14
Distance: 2.248.671 km
Filters: CL1 and GRN
4x enlarged


Attached Image

Date: 2007-02-14
Distance: 2.248.666 km
Filters: CL1 and CL2
4x enlarged

Attached Image

Date: 2007-02-14
Distance: 2.248.655 km
Filters: CL1 and UV3
4x enlarged

Attached Image

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.
Go to the top of the page
 
+Quote Post
alan
post Feb 16 2007, 09:27 PM
Post #47


Senior Member
****

Group: Members
Posts: 1887
Joined: 20-November 04
From: Iowa
Member No.: 110



Confirmed
http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
Go to the top of the page
 
+Quote Post
ugordan
post Feb 16 2007, 09:35 PM
Post #48


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:
Attached Image


So... Saturn really is yellow. Who would have known!


--------------------
Go to the top of the page
 
+Quote Post
elakdawalla
post Feb 16 2007, 10:20 PM
Post #49


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.
Attached Image


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.
Go to the top of the page
 
+Quote Post
ugordan
post Feb 16 2007, 10:25 PM
Post #50


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


--------------------
Go to the top of the page
 
+Quote Post
elakdawalla
post Feb 16 2007, 10:31 PM
Post #51


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 smile.gif

--Emily


--------------------
My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
Go to the top of the page
 
+Quote Post
Rob Pinnegar
post Feb 17 2007, 02:28 PM
Post #52


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.
Go to the top of the page
 
+Quote Post
TritonAntares
post Feb 18 2007, 03:47 PM
Post #53


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.
Go to the top of the page
 
+Quote Post
tasp
post Feb 18 2007, 07:31 PM
Post #54


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 . . . .
Go to the top of the page
 
+Quote Post
nprev
post Feb 19 2007, 12:04 AM
Post #55


Merciless Robot
****

Group: Admin
Posts: 8783
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.
Go to the top of the page
 
+Quote Post
Rob Pinnegar
post Feb 19 2007, 12:09 AM
Post #56


Member
***

Group: Members
Posts: 509
Joined: 2-July 05
From: Calgary, Alberta
Member No.: 426



QUOTE (nprev @ Feb 18 2007, 05:04 PM) *
... but will Cassini get any really good views of the dark/light border areas this September?

Yes. Mostly on the side of Iapetus that faces away from Saturn.
Go to the top of the page
 
+Quote Post
TritonAntares
post Feb 19 2007, 12:48 PM
Post #57


Member
***

Group: Members
Posts: 288
Joined: 28-September 05
From: Orion arm
Member No.: 516



QUOTE (nprev @ Feb 19 2007, 01:04 AM) *
... 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...

Attached Image

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... smile.gif
CASSINI will follow the equatorial ridge from east to west first looking at a cresent Iapetus.

Btw, there will be two far encounters before:
Attached Image

April 15th

Attached Image

July 5th

Both will show some parts of the terra incognita including a huge bassin about 400-500 km in diameter... wink.gif

Bye.
Go to the top of the page
 
+Quote Post
nprev
post Feb 19 2007, 03:30 PM
Post #58


Merciless Robot
****

Group: Admin
Posts: 8783
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.
Go to the top of the page
 
+Quote Post
tasp
post Feb 19 2007, 03:38 PM
Post #59


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.
Go to the top of the page
 
+Quote Post
tasp
post Feb 19 2007, 03:41 PM
Post #60


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 . . .
Go to the top of the page
 
+Quote Post

12 Pages V  « < 2 3 4 5 6 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 29th March 2024 - 03:18 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.