IPB

Welcome Guest ( Log In | Register )

Rev 153 - Sep 3-22, 2011 - Titan T78, Also Pallene, Tethys, Enceladus, and Hyperion
Floyd
post Sep 2 2011, 03:14 PM
Post #1


Member
***

Group: Members
Posts: 627
Joined: 4-September 06
From: Boston
Member No.: 1102



From Looking Ahead: Rev153: Sep 3 - Sep 22 '11

A lot going on this revolution:

Sixty-one ISS observations are planned for Rev153, the majority designed to monitor cloud systems in Saturn's atmosphere. The spacecraft also will encounter a number of Saturn's moons, including Titan, Pallene, Tethys, Enceladus, and Hyperion, for which ISS will acquiring imaging.

ISS will image the L5 Lagrange point (60 degrees behind satellite) regions of the moons Iapetus, Rhea and Dione to see if they have Trojan’s like Dione/Polydeuces and Tethys/Calypso.

Titan encounter Sept 12. CIRS, VIMS, UVIS, INMS, CAPS, ISS
Imaging Enceladus polar plume from night side at 42,224 km and two mosaics of sub-Saturn hemisphere. Sept 13
Imaging Tethys from 300,00 km Sept 13
Image Pallene from 25,960 km (38x26 pixels at that distance as only 3.6 x 2.5 miles) Sept 13
Image Hyperion from 58,015 km—a little further than last month. Sept 16.
Color image of Tethys passing in front of Titan's south polar hazes. Sep 16.
Mutual events Enceladus in front of Titan with Rings and Pandora in background Sept 17.


--------------------
Floyd
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
remcook
post Sep 14 2011, 07:12 AM
Post #2


Rover Driver
****

Group: Members
Posts: 1002
Joined: 4-March 04
Member No.: 47



Of course there's some shadows/darkness behind the bright bit, but the fact that the bright 'line' seems to go up in altitude significantly looks quite strange to me. There seems to be either a big pile-up of haze at the pole (polar cap?) + shadow, or a local increase in haze scattering, like the detached haze layer.
Very nice images by the way (yet again!) smile.gif
Go to the top of the page
 
+Quote Post
ugordan
post Sep 14 2011, 07:39 AM
Post #3


Senior Member
****

Group: Members
Posts: 3569
Joined: 1-October 05
From: Croatia
Member No.: 523



I was thinking the increase in brightness could come from some funky forward-scattering properties of the orange haze ahead. To my eye it only appears to be pronounced in longer wavelengths. I can't think of a mechanism that would do that, though.

Also, did anyone actually try measuring pixel values to verify it really is brighter and not some optical illusion? I was too lazy to do that myself yesterday.


--------------------
Go to the top of the page
 
+Quote Post
ngunn
post Sep 15 2011, 07:36 PM
Post #4


Senior Member
****

Group: Members
Posts: 3158
Joined: 4-November 05
From: North Wales
Member No.: 542



QUOTE (ugordan @ Sep 14 2011, 08:39 AM) *
I was thinking the increase in brightness could come from some funky forward-scattering properties of the orange haze ahead. To my eye it only appears to be pronounced in longer wavelengths.


That sounds very plausible to me, and is a more economical hypothesis than my earlier suggestion as it does not invoke diurnal changes. We know that the orange haze scatters photons predominantly into a narrow forward cone. Near the limb the uppermost part of that cone would miss the surface and escape tangentially into the upper haze layers. An observer inside the bright streak looking back toward the rising or setting sun would be doubly dazzled - by the sun itself and also by an exceptionally bright patch in the orange haze just below it, looking almost like a specular reflection.

It works for me (in a purely handwaving way!) until the experts come up with a better explanation.

That said, the possibility of diurnal changes in the haze layers cannot be altogether discounted as far as I'm aware.

Gordan - a direct question/request: You say the streak looks brighter at longer wavelengths. Can you construct an image, maybe in stretched colours, that shows this? The spectrum of the streak would be a clincher, I think.
Go to the top of the page
 
+Quote Post

Posts in this topic
- Floyd   Rev 153 - Sep 3-22, 2011 - Titan T78   Sep 2 2011, 03:14 PM
- - Juramike   Saw these images come down of a starfield as taken...   Sep 7 2011, 02:42 AM
- - Toma B   My God, it's full of stars!   Sep 7 2011, 07:58 AM
- - Decepticon   Very funny!   Sep 7 2011, 08:46 AM
- - JTN   Here's what astrometry.net makes of it (I won...   Sep 7 2011, 11:51 AM
|- - Juramike   QUOTE (JTN @ Sep 7 2011, 06:51 AM) Here...   Sep 7 2011, 01:46 PM
- - Floyd   From Looking Ahead Rev 153: ISS begins its observa...   Sep 7 2011, 12:27 PM
- - Juramike   Paaliaq the Pixel! Four frame animation crate...   Sep 10 2011, 01:59 PM
- - titanicrivers   Nice montage Mike and impressive ID by Astrometry....   Sep 11 2011, 05:08 AM
|- - ugordan   Titan on September 9, CB3/GRN/UV3 plus some ...   Sep 11 2011, 12:34 PM
|- - ugordan   Some lovely shots of Titan's south pole are av...   Sep 13 2011, 04:25 PM
|- - Stu   Absolutely beautiful...   Sep 13 2011, 07:27 PM
- - remcook   Wow, that detached haze layer is doing some funky ...   Sep 13 2011, 09:43 PM
|- - ugordan   Here's the WAC companion to that NAC shot, sou...   Sep 13 2011, 10:09 PM
- - ngunn   I think there could be diurnal changes in the uppe...   Sep 13 2011, 10:09 PM
- - Bjorn Jonsson   Seems partially due to Titan's own shadow but ...   Sep 14 2011, 12:43 AM
- - remcook   Of course there's some shadows/darkness behind...   Sep 14 2011, 07:12 AM
|- - ugordan   I was thinking the increase in brightness could co...   Sep 14 2011, 07:39 AM
|- - Bjorn Jonsson   QUOTE (ugordan @ Sep 14 2011, 07:39 AM) A...   Sep 14 2011, 08:15 PM
|- - ngunn   QUOTE (ugordan @ Sep 14 2011, 08:39 AM) I...   Sep 15 2011, 07:36 PM
|- - ugordan   QUOTE (ngunn @ Sep 15 2011, 09:36 PM) Gor...   Sep 15 2011, 09:07 PM
- - remcook   As far as I can tell from stretching etc. it's...   Sep 14 2011, 08:10 AM
- - Juramike   There actually IS more material at the inner bound...   Sep 14 2011, 02:13 PM
- - remcook   Very cool paper. It's amazing how much Cassin...   Sep 14 2011, 07:05 PM
- - Ian R   This shot of Tethys has it all: a giant crater, a ...   Sep 16 2011, 11:39 PM
|- - Gladstoner   .   Sep 17 2011, 08:42 PM
- - PDP8E   Fabulous image Ian! It is so tempting to say t...   Sep 17 2011, 02:02 AM
- - Juramike   Another version of Tethys RGB[IR1,GRN,UV3]:   Sep 17 2011, 03:29 AM
- - Juramike   5-frame mosaic of images taken along Enceladus...   Sep 17 2011, 03:34 PM
|- - scalbers   QUOTE (Juramike @ Sep 17 2011, 04:34 PM) ...   Sep 18 2011, 07:53 PM
- - Floyd   Thanks Mike. I was hoping someone would do someth...   Sep 17 2011, 04:11 PM
- - elakdawalla   Go read Paul "DrShank" Schenk's blog...   Sep 17 2011, 09:17 PM
|- - Gladstoner   .   Sep 18 2011, 10:57 AM
- - Adam Hurcewicz   My colour version of Hyperion (~93 000 km from Cas...   Sep 19 2011, 11:51 AM
- - Phil Stooke   Very nice! Phil   Sep 19 2011, 08:32 PM
- - Gladstoner   .   Sep 19 2011, 10:12 PM
- - ngunn   It's hard to pick a favourite from this sequen...   Sep 20 2011, 07:50 PM
- - Astro0   After downloading that lastest sequence of mutual ...   Sep 20 2011, 11:10 PM
- - elakdawalla   Pretty awesome, isn't it? I badly want to col...   Sep 21 2011, 03:47 AM
|- - ugordan   QUOTE (elakdawalla @ Sep 21 2011, 05:47 A...   Sep 21 2011, 07:58 AM
- - Adam Hurcewicz   Yesterday I upload to youtube animation of occult ...   Sep 21 2011, 07:11 AM
- - elakdawalla   I didn't notice that one! And it doesn...   Sep 21 2011, 02:37 PM
|- - pat   Sorry, its a 6th magnitude star, TYC 333-1215-1/HD...   Sep 21 2011, 06:56 PM
- - elakdawalla   Thanks, pat!   Sep 21 2011, 07:00 PM
- - Ian R   A random interjection: here's a nice little sh...   Sep 24 2011, 12:28 PM
- - kyokugaisha   Here's my rough attempt at a RGB composite of ...   Sep 24 2011, 03:07 PM
- - Ian R   *APPLAUDS*   Sep 24 2011, 04:29 PM
- - elakdawalla   THAT's the one I was waiting to see, thanks   Sep 24 2011, 04:58 PM
- - ngunn   Excellent!   Sep 24 2011, 07:41 PM
- - Juramike   Methanovision RGB[MT3,MT2,CB2] composite from Sept...   Sep 25 2011, 08:56 PM
- - jasedm   Pallene raw image from 13th September, cleaned up ...   Sep 28 2011, 06:00 PM
- - Phil Stooke   My version. This will be really nice when we get ...   Sep 29 2011, 07:50 PM
- - jasedm   Nice. I'm sure I can see a crater on the satur...   Sep 30 2011, 12:50 PM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 25th October 2014 - 01:29 AM
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 a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.