Unveiling Titan

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>To say they are surface features is likewise unsubstantiated.<p><hr /></p></p></blockquote><br /><br />Well, the alternative would be atmospheric features, and they're awfully static for those. <img src="/images/icons/wink.gif" /> The only comparable example I can think of is the Great Red Spot, and even that changes dramatically over time. So far, the raw images are pretty consistent with past imagery, both from Cassini itself earlier this year and from both Hubble and ground-based observatories. <br /><br />It's a very good bet that they're surface features. What they actually *are*, however, is anybody's guess right now. Of course, that just makes it all that much more fun. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[volcanopele2]

While the surface features are open to interpretation, the fact we are seeing the surface or at the VERY least VERY near surface fog that is geographically contained (though I find that unlikely) appears to be almost surely the case.

 

[alexblackwell]

PIA06125: Revealing Titan's Surface

 

[peteb]

Hmmm, does that look like a crater in the dark area in the processed image on the right?

 

[rogers_buck]

Where's the ocean? I brought my board.

 

[rogers_buck]

I wish they'd put that one processed picture of Xanadu back up. That was great. Are those ice mountains? <br /><br />

 

[volcanopele2]

yes, that does.

 

[thalion]

Maybe this is an instrumental limitation, or an optical illusion, but to me the current imaged area looks surprisingly smooth. Then again, there also aren't any shadows to illustrate surface relief. Perhaps we'll get a better idea of how rough the place is on later flybys.

 

[imran10]

The mystery deepens.<br /><br />Titan's Big Surprise<br />Henry Bortman<br />Astrobiology Magazine<br />October 27, 2004<br /><br /><i>Instruments aboard the Cassini spacecraft have sent back the most detailed images ever captured of the surface of Saturn's giant moon, Titan. They've also presented scientists with a major mystery. There's a huge cloud formation over the moon's south pole, spanning 1000 kilometers at its widest. That's no surprise; scientists expected it to be there. But they also expected it to be made of methane. And it isn't.</i>

 

[thechemist]

They are clouds alright, but of what ?<br /><br />I just read the article in Astrobiology magazine linked by imran. <br /><br />We have no clue at the moment, but this is big, as it might change what we think we know about Titan ! <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[imran10]

Just a reminder - there will be a press conference today from 12 - 1pm EDT on NASA TV where they will be discussing the science (possibly the radar) results.

 

[centsworth_II]

<font color="yellow">"They are clouds alright, but of what?"</font><br /><br />The three things I got form the 10/27 briefing were:<br />1. The clouds are not methane<br />2. They have grown in size since the first fy-by<br />3. the individual particles forming them are about five times larger (5 micron vs. 1 micron) than the particles forming the global haze.<br /><br />There was no speculation about what the clouds could be made of, but is it possible that they are made of the same substance(s) as the global haze, and only the larger particle size is responsible for their appearance?<br /><br />Also, note that surprise was expressed at the briefing that the obviously (visually) different light and dark areas on the surface were so far not showing any great differences in their compositions. <br /> <div class="Discussion_UserSignature"> </div>

 

[thechemist]

I find this possibility from the Astrobiology article highly unlikely:<br /><br /><i>"Another possibility, he says, is that "it's some sort of organic goo. It could be some sort of organic polymer, essentially plastic particles. Maybe little polystyrene foam balls. Who knows?" "</i><br /><br />Briefing starts right about now ! Let's see ! <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[yurkin]

The Cassini radar guy said they found a large body of fluid about the size of Lake Tahoe. At least if they took a radar map of earth with this same instrument it would be interpreted as a lake. Looks like the case for oceans on Titan just got a little bit stronger.

 

[imran10]

Well so much for ice mountains.<br /><br />Titan's smooth surface baffles scientists<br />LARRY COPENHAVER<br />Tucson Citizen <br />October 28, 2004<br /><br />"Scientists expected a few rough spots when their space drone snapped close-range images of Titan, Saturn's largest moon.<br /><br />Instead, the planetlike moon appears to have a "bizarre," mysteriously smooth surface, and Tuesday's images have left them in a state of wonder.<br /><br />" "The surface looks like it has been resurfaced," said University of Arizona professor Robert H. Brown."<br /><br />"According to radar reports, there are no hills or valleys more than 50 meters high or deep."<br /><br />

 

[alexblackwell]

Cassini's First Close Flyby of Titan: So Much Information, So Few Answers (Yet)<br />by Emily Lakdawalla<br />The Planetary Society<br />October 28, 2004

 

[silylene old]

Wow, is all I can say after reading this:<br />Cassini's First Close Flyby of Titan: So Much Information, So Few Answers (Yet) <br /><br />Rivers perhaps are shown in one photo on the feature called "Great Britain"....wow! <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[silylene old]

There do appear to be a couple of smallish circular features in the black areas, with lighter colored rims. I don't think these arise from lense defects. If these are not impact craters, are we suggesting these are lense defects, or visual anomolies, or perhaps volcanic calderas?<br /><br />I can post a picture if you cannot find them. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[toymaker]

Wow indeed, a truly alien world likes of which we haven't seen before...I am in awe...

 

[volcanopele2]

There are some circular features in the dark regions off the "coast" of Xanadu which are NOT lens defects or dust on the lens. Currently they are candidate craters and we really can go no further than that without some data on topography. one the face of it we see broken rings of bright material. We see a dark, circular spots at the upstream end of one of the stream-line forms, similar to those seen on Mars. However, without topography we can't know for sure. Volcanic calderas are certainly a possibility, perhaps something like what we see on Io (though those have more linear edges as opposed to being perfectly round.

 

[mooware]

You know I've been looking at these Titan pics, and I was thinking that the white areas were clouds and the dark area is what was underneath. It just dawned on me that the white and black areas are both the surface.. Duh.. <br /><br />Very strange indeed.. I'm looking forward to the Hyugens probe, and more flybys.<br /><br />

 

[mooware]

Speaking of probes.. I understand that Hyugens has camera's on board. But, I'm thinking that the haze may be so thick we may not see anything. Kind of like being in the middle of a good London Fog.<br /><br /><br />

 

[alexblackwell]

PIA06984: 'Black Cat' on Titan

 

[alexblackwell]

<i>There are some circular features in the dark regions off the "coast" of Xanadu which are NOT lens defects or dust on the lens. Currently they are candidate craters and we really can go no further than that without some data on topography.</i><br /><br />Although I agree that these small "circular features" do indeed look like small bowl-shaped impact craters, it's hard for me to readily accept it. Aside from the lack of topographic data you allude to, the solar phase phase angle, based on the imaging geometry Carolyn noted yesterday, combined with the ubiquitous haze, which tends to subdue shadows due to the scattered light, makes it hard for me believe in these sharp rims. Also, Titan's atmospheric thickness, like Venus', has an impactor size cutoff threshold that would seem to preclude primary or even secondary craters below a certain diameter, though offhand I'm not familiar with what this value actually is.<br /><br />That said, I wouldn't be surprised if the "circular features" are indeed craters, perhaps even cyrovolcanic cones or calderas.

 

[volcanopele2]

Well, I've been thinking that we are seeing bright rims in at least two cases which might be akin to the bright streaks seen on Phoebe, i.e. dark material is falling down the walls of the crater revealing bright material beneath.