T16 RADAR SAR Swath, Land o' lakes |
T16 RADAR SAR Swath, Land o' lakes |
Guest_AlexBlackwell_* |
Jul 25 2006, 06:15 PM
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#31
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I was in on that. If you are like me, you've thought about that bet over a hundred times since then. The poor fellow on the other side became mighty scarce (prematurely) after one of the first flybys (even before Huygens). Yes, he should get his checkbook out I seem to recall he mentioned that he was going offline to do graduate work for, I believe, David Stevenson at Caltech. |
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Jul 25 2006, 07:08 PM
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#32
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Member Group: Members Posts: 540 Joined: 17-November 05 From: Oklahoma Member No.: 557 |
... or a more languid rate of coverage, making few observations (perhaps many "blind" flybys with few or no observations), but lasting well into the next Titanian seasons. Obviously, flybys of the other satellites would subtract from the Titan observations. These lakes might relegate Iapetus, aside from its late-primary-mission closeup, to "see you next mission" status. Enceladus will still hold its own as an extended mission candidate, but the other icy moons are looking forgettable in comparison. Another slow loop out to Iapetus with a non demanding slow flyby is consistant with "a more languid" mission scenerio extending the time past equinox. Especially if you're not too tight in your targeting. but only want to get close enough, say ten to fifty thousand km, to complete coverage of areas previously missed. All of this, provided of course, that it's not too difficult to get into this orbit in the first place. I'm still holding out for some kind of second Iapetus pass. |
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Guest_Myran_* |
Jul 25 2006, 09:00 PM
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#33
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When UMSF got so slow yesterday I wondered if something big was up with just too many visitors.
And im now wondering if this one might have caused it. Its such a major find, another body in the solar system with liquid lakes on the surface. Its mainstream CNN news now BTW. |
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Guest_AlexBlackwell_* |
Jul 25 2006, 09:09 PM
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#34
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Another slow loop out to Iapetus with a non demanding slow flyby is consistant with "a more languid" mission scenerio extending the time past equinox. Especially if you're not too tight in your targeting. but only want to get close enough, say ten to fifty thousand km, to complete coverage of areas previously missed. All of this, provided of course, that it's not too difficult to get into this orbit in the first place. I'm still holding out for some kind of second Iapetus pass. Getting back to Iapetus during an extended mission would be nice, but as I mentioned previously, doing so under most of the EM options being considered would require a lot of work and some not-so-minor sacrifice(s) of other, presumably more important, science objective(s). |
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Jul 25 2006, 09:37 PM
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#35
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Member Group: Members Posts: 540 Joined: 17-November 05 From: Oklahoma Member No.: 557 |
Getting back to Iapetus during an extended mission would be nice, but as I mentioned previously, doing so under most of the EM options being considered would require a lot of work and some not-so-minor sacrifice(s) of other, presumably more important, science objective(s). My hope is that somehow they can do detailed coverage of the "snowman" plus points to the east and southeast of there. Of course, I'll accept the fact that all this has to be incidental to additional coverage of Titan and Enceladus. I'm just hoping some mission planners are on the lookout for an opportunity to work in some additional Iapetus coverage on the side. Wouldn't a few extra liters of propellant be nice right about now? Well, can't have everything. |
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Guest_AlexBlackwell_* |
Jul 25 2006, 09:43 PM
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#36
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My hope is that somehow they can do detailed coverage of the "snowman" plus points to the east and southeast of there. Of course, I'll accept the fact that all this has to be incidental to additional coverage of Titan and Enceladus. I'm just hoping some mission planners are on the lookout for an opportunity to work in some additional Iapetus coverage on the side. Wouldn't a few extra liters of propellant be nice right about now? Well, can't have everything. It's doable, to be sure. And Cassini prop margins (which have always been conservatively estimated) are much better than predicted. If anything nixes a close Iapetus flyby during the EM, it'll probably be a competing faction(s) of scientists who wanted to do something else that precluded it. |
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Jul 25 2006, 10:07 PM
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#37
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Junior Member Group: Members Posts: 40 Joined: 11-November 05 Member No.: 550 |
Just imagine what it would be like to be walking towards the shore, then look out over the hydrocarbon lake, with Saturn above.
We've seen plenty of artists renditions depicting such a scene....but now its reality! Super! |
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Jul 25 2006, 10:19 PM
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#38
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Just imagine what it would be like to be walking towards the shore, then look out over the hydrocarbon lake, with Saturn above. Yep, I can imagine that... it would be sooo beautiful... sadly, as I understand it, I think that from the lakes' altitude (i.e low) Titan's atmosphere would be far too dense and smoggy to allow you to see Saturn... Maybe if you climbed one of the mountains or (suspected) volcanic caldera you might. MIGHT just see a hint of Saturn through the clouds, but I wouldn't bet the Hab on it... -------------------- |
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Guest_AlexBlackwell_* |
Jul 25 2006, 10:22 PM
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#39
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Just imagine what it would be like to be walking towards the shore, then look out over the hydrocarbon lake, with Saturn above. Maybe it's time for Ralph Lorenz to update his now-famous flying-and-swimming-on-Titan sequences in "95 Worlds and Counting." |
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Jul 25 2006, 10:41 PM
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#40
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
In terms of Titanian skygazing, note that the ratio of sunshine (daytime) vs. saturnshine (selected nighttimes) would be much smaller than sunshine vs. moonlight ("moonshine"?!) on Earth. Something like ~6 magnitudes. It would probably be bright enough to read by saturnshine on a Titan night. However, that would probably take the form of an extremely diffuse light from the whole sky, or at least most of it. It would probably look like the view you get looking up at a cloudy sky in a city on Earth, with the clouds lit by the lights below (on Titan: haze lit from the Saturn above). It would be interesting to know if the light were in any way localized, ie, concentrated in the general part of the sky where Saturn was instead of just all over. I think it would be pretty well spread out. Now, if you had IR vision, you might see Saturn pretty distinctly as an object with fuzzy boundaries.
The polar regions of Titan would only have a side-looking view of Saturn, which would cut the light input quite a bit. So you'd have a nicer experience if there were a midlatitude lake. |
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Jul 28 2006, 08:25 AM
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#41
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Junior Member Group: Members Posts: 51 Joined: 12-March 06 From: Zurich, Switzerland Member No.: 703 |
I’m a little puzzled by the latest News Release on the T16 RADAR swath:
http://saturn.jpl.nasa.gov/news/press-rele....cfm?newsID=679 Cassini scientist are now quite confident that at least some of the radar dark spots are indeed lakes (which is great!). They further state that “the lakes are most likely the source of hydrocarbon smog in the frigid moon's atmosphere”. I thought that the hydrocarbon smog was generally hypothesized to originiate from organic molecules formed by photodissociation of methane in Titan’s upper atmosphere. So do they presume that the hydrocarbon smog comes indirectly from methane evaporating from the polar lakes and thus replenishing Titan's methane atmosphere? Are these comparatively small lakes really sufficient to replenish the atmospheric methane? At the northern hemisphere, they seem to be quite restricted the latitudes above 75 degrees. Furthermore, some of these “lakes” appear to be only partly wet at the moment and probably do not harbor large quantities of liquid methane. Isn’t it still more likely that methane from Titan’s interior (released by cryovolcanoes, low temperature serpentinization, whatever) prevents the atmospheric methane depletion? At least, there is some circumstantial evidence for volcanic activity, like the detection of 40Ar by Huygens’ GCMS. |
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Jul 28 2006, 09:04 AM
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#42
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
I’m a little puzzled by the latest News Release on the T16 RADAR swath: http://saturn.jpl.nasa.gov/news/press-rele....cfm?newsID=679 Cassini scientist are now quite confident that at least some of the radar dark spots are indeed lakes (which is great!). They further state that “the lakes are most likely the source of hydrocarbon smog in the frigid moon's atmosphere”. That statement caught my eye, too. I think that's stretching it a bit. The lakes contain methane which in turn evaporates into the atmosphere where it's broken down by UV light to produce smog. So technically, they are the source of the smog (not a direct source, though!). The wording is a bit awkward. I agree with you on the point of lakes being just a temporary reservoir of methane, cryovolcanism is probably the mechanism by which Titan's methane is replenished. Without it, the lakes would eventually all dry up because all methane would be destroyed on a fairly short timescale. That is, unless there's actually a vast reservoir of methane hiding below the surface. The question would then be: where'd THAT come from? -------------------- |
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Jul 28 2006, 10:33 AM
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#43
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Member Group: Members Posts: 688 Joined: 20-April 05 From: Sweden Member No.: 273 |
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Aug 1 2006, 04:42 PM
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#44
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Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Yes, he should get his checkbook out I seem to recall he mentioned that he was going offline to do graduate work for, I believe, David Stevenson at Caltech. I was kinda half joking Imagine my surprise when I checked my mailbox this morning... -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Aug 8 2006, 02:55 PM
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#45
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Member Group: Members Posts: 159 Joined: 4-March 06 Member No.: 694 |
Just one simple question. When will we able to see the whole T16 SAR swath?
I know it started at about 53S latitude and almost reached the north pole of Titan. And we have only seen the bits near the north pole! -------------------- I call heaven and earth to witness against you this day, that I have set before thee life and death, the blessing and the curse; therefore choose life, that thou mayest live, thou and thy seed.
- Opening line from episode 13 of "Cosmos" |
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