My Assistant
Titan Surface Features |
Dec 16 2004, 05:43 PM
Post
#1
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
This thread is intended as a discussion of Titan's surface features, possible analogs, wild ideas, etc. To get started, I am posting a list below of all relevent images along with observation request name so everyone is on the same page. The images to be released today will certainly provide plenty of fodder for discussion.
Pre-SOI Approach Map http://ciclops.lpl.arizona.edu/view.php?id=214 Reprocessed Approach Map http://ciclops.lpl.arizona.edu/view.php?id=482 T0 SPOLEB http://ciclops.lpl.arizona.edu/view.php?id=253 WIND002 http://ciclops.lpl.arizona.edu/view.php?id=252 Approach Map + SPOLEB http://ciclops.lpl.arizona.edu/view.php?id=627 Ta MOVIEB frame http://ciclops.lpl.arizona.edu/view.php?id=515 LRMONITOR (unprocessed) http://ciclops.lpl.arizona.edu/view.php?id=519 Ta MONITOR http://ciclops.lpl.arizona.edu/view.php?id=575 Ta Early processing Montage http://ciclops.lpl.arizona.edu/view.php?id=533 MEDRES002 http://ciclops.lpl.arizona.edu/view.php?id=541 HIRES frame showing Huygens landing site area http://ciclops.lpl.arizona.edu/view.php?id=535 Tb MOVIED http://ciclops.lpl.arizona.edu/view.php?id=654 EUVFUV002 http://ciclops.lpl.arizona.edu/view.php?id=657 -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
![]() |
| Guest_Sunspot_* |
Dec 16 2004, 06:18 PM
Post
#2
|
|
Guests |
Cool, thanks for posting these.
Any more theories on what the dark areas might be? As large bodies of liquid seem to have fallen out of favour could we be seeing regions where the crust has pulled apart exposing darker material from below? |
|
|
|
Dec 16 2004, 11:33 PM
Post
#3
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Here are some more. Hope you like them.
Ta Ta_REGMAP http://photojournal.jpl.nasa.gov/catalog/PIA06158 Tb Tb_REGMAP http://photojournal.jpl.nasa.gov/catalog/PIA06159 MOVIEC http://photojournal.jpl.nasa.gov/catalog/PIA06154 -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
| Guest_Sunspot_* |
Dec 17 2004, 12:16 AM
Post
#4
|
|
Guests |
QUOTE (volcanopele @ Dec 16 2004, 11:33 PM) Here are some more. Hope you like them. Ta Ta_REGMAP http://photojournal.jpl.nasa.gov/catalog/PIA06158 Tb Tb_REGMAP http://photojournal.jpl.nasa.gov/catalog/PIA06159 MOVIEC http://photojournal.jpl.nasa.gov/catalog/PIA06154 What a coincedence, I just found these images on the Cassini press release images page and not having seen them before was going to post links to them |
|
|
|
| Guest_Sunspot_* |
Dec 17 2004, 12:26 AM
Post
#5
|
|
Guests |
So we maybe seeing the first evidence of impacts on Titan in the image below... which of the flybys will give us the best view of this hemisphere? Have scientists completely ruled out the possibilty that these dark areas could be liquid?
|
|
|
|
Dec 17 2004, 02:03 AM
Post
#6
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
QUOTE (Sunspot @ Dec 16 2004, 05:26 PM) So we maybe seeing the first evidence of impacts on Titan in the image below... which of the flybys will give us the best view of this hemisphere? Have scientists completely ruled out the possibilty that these dark areas could be liquid? In T3 we get a SAR swath over that multi-annulus structure. T4 I know we get coverage over the sub-Saturnian hemisphere. -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
Dec 18 2004, 03:11 AM
Post
#7
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
Whats the difference in brightness between the bright and dark areas. How does this compare to features on other moons, for example the difference between the mare and highlands on the moon or the bright and dark terrain on Ganymede.
|
|
|
|
Dec 18 2004, 05:33 AM
Post
#8
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Dark terrain: liquid or not? Well, based on the data returned from VIMS and ISS, the dark terrain seen in Ta and Tbis likely not liquid, or at least not all of if. However, this doesn't rule out smaller patches of liquid, perhaps like Sisi's cat from the Ta RADAR swath. In addition, the dark features seen in SPOLEB from T0 seem to be more consistent morphologically as bodies of liquid. Regarding the albedo difference, VIMS at 2 microns says that its an order of magnitude. ISS at 938 nm seems to show at 20-30% difference.
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
Dec 18 2004, 05:38 AM
Post
#9
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
The order of magnitude could also come from comparing the brightest Titan terrain in SE Xanadu and the darkest terrain SE of Great Britain. Keep in mind that out side of the definied dark terrain and Xanadu, much of Titan is in shades of grey. But even then I don't think we are seeing an order of magnitude difference (by we, I mean ISS)
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
| Guest_Sunspot_* |
Dec 18 2004, 01:01 PM
Post
#10
|
|
Guests |
http://news.com.com/Tantalizing+clues+in+p..._3-5495111.html
Meanwhile, the "ocean" on Titan may not be. Instead of a liquid body of water, the dark mass seen on the surface of the Titan may be a viscous fluid flowing onto the white "coastline," Parco said. Then again, the viscous fluid could be flowing down from a higher altitude, like a glacier, onto the white mass. Right now, researchers only have two-dimensional images. Often, scientists look at the images and analogize it to information they know about on Earth, such as island chains or coastlines, she said. Stronger conclusions may be possible with the availability later of images that are more precise, or stereoscopic images that include shadows or information on altitude. Some typos in that artice lol...and I think they probably meant to say liquid methane. |
|
|
|
| Guest_BruceMoomaw_* |
Dec 18 2004, 01:27 PM
Post
#11
|
|
Guests |
I'll stick by my earlier theory: it's been remarked on at two press conferences now that the dark streaks look very much as though they've been laid down by Titan's west-to-east winds -- and when you look at the bright "islands" in the middle of the darker area in that latest image, you see areas of an intermediate gray albedo consistently pointing downwind from the islands. (These are very clear to anyone, and they too were mentioned at Thursday's AGU press conference.)
I think the dark material has been, to a very great degree, wind-distributed. I think it consists largely -- and perhaps entirely -- of solid particles of dark organic smog, blown over the surface in the same way as Mars' fine dust, and thus tending to accumulate in low-lying parts of Titan's surface (and also resulting in gray "wakes" of reduced dark material in the leeward wind shadows of the higher-altitude bright "islands"). Dimitrov and Bar-Nun reported in the Feb. 2002 Icarus that their lab experiments indicated that Titan's solid smog particles are likely to be hard-surfaced and non-sticky, greatly increasing the extent to which they can be wind-blown even after landing. The real question in my mind is how the slow rain of liquid ethane which is also supposed to be radiation-generated in Titan's upper atmosphere affects all this. Does it provide a further means by which the solid dark smog particles are washed off higher-altitude terrain? Does it mix with the smog particles to form a sludgy cryogenic mud (which -- due to the very low vapor pressure of liquid ethane in Titan's atmosphere -- would literally never dry out and harden)? |
|
|
|
Dec 18 2004, 05:54 PM
Post
#12
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Moderator Posts: 3242 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
both are good possibilities, Bruce. However, one of my thoughts is that the bright stuff is the hardened particulates getting blown down wind. There are other possibilitites. Cool ones. The idea that the dark material is a high viscosity mix of particulates and ethane, or some gunk is one I like as well.
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
|
Dec 18 2004, 07:12 PM
Post
#13
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
QUOTE This thread is intended as a discussion of Titan's surface features, possible analogs, wild ideas, etc. I'll start with a wild idea. The dark area on Titan is a much larger version of these features on Europahttp://photojournal.jpl.nasa.gov/jpegMod/PIA02099_modest.jpg http://photojournal.jpl.nasa.gov/jpegMod/PIA01125_modest.jpg http://photojournal.jpl.nasa.gov/jpegMod/PIA01127_modest.jpg It circles nearly all the way around the equator because it hapened before titan was tidally locked. |
|
|
|
Dec 18 2004, 08:02 PM
Post
#14
|
|
|
Newbie ![]() Group: Members Posts: 9 Joined: 3-November 04 Member No.: 106 |
Why should Titan be tidally locked - what means it ???
It is in a quite eccentric orbit with e=0.029. As a consequence, there will be quite substantial tides with about 15.945 days full period and a magnitude for an ideal fluid sphere in the range of 20 meters or more. There are tides on the "tidally locked" but eccenric orbiting earth moon, there are enormous tides on Jo with a very small forced eccentricity. I have somme feeling that in recent months, the tidal influence is somewhat neglected.. If I remeber correctely, the late Carl Sagan made some (published) calculations, showing that a fluid surface must be 400 m or more deep in order to keep the tidal backreaction onto the eccentricity low. I wonder why Titan has such a high eccentricity - it cannot be forcing of other moons - their mass is rather small. |
|
|
|
Dec 18 2004, 08:27 PM
Post
#15
|
|
![]() Senior Member ![]() ![]() ![]() ![]() Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
By not being tidally locked I meant while it was still rotating with respect to Saturn rather than rocking because of the eccentricity like it is now. The dark areas appear to be in a band around the equator, that seemed to be the simplest explanation. Like I said this is a wild idea.
|
|
|
|
![]() ![]() |
|
Lo-Fi Version | Time is now: 15th December 2024 - 10:50 PM |
|
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE 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. |
|