Titan flyby next week!

[Hoover]

Well, before I start blaming the camara man I guess maybe I will have to accept that it really looks like that. It doesn't matter what resolution it is, if something is inherently blurry looking ...

And maybe I'm being impatient. I was hoping they'd use some parallax effects to get a more 3D picture of Titan. But those kinds of pictures take a time to put together.

Its also very possible they concentrated on Radar this time around. This was supposed to be reconnaissance for the Huygens probe.

Now who is going to clean the dust off the lens?

[Evil Dr Ganymede]

Well, before I start blaming the camara man I guess maybe I will have to accept that it really looks like that. It doesn't matter what resolution it is, if something is inherently blurry looking ...

And maybe I'm being impatient. I was hoping they'd use some parallax effects to get a more 3D picture of Titan. But those kinds of pictures take a time to put together.

Yes, you're being impatient . Don't forget, NASA don't even have to be showing us the raw images (in fact, in earlier missions, NASA didn't show us the raw images at all - all we had were the odd press releases, if we wanted raw images we'd have to wait a year or so for the data embargo to be lifted).

Believe me, I'm probably even more frustrated that Titan is so tenaciously holding onto its secrets... but we WILL see through the haze.

You can't get 3D stereo out of something this blurry. Again, the Radar should be much more useful in getting topography data.

Now who is going to clean the dust off the lens?

Nobody. That's there for good. Fortunately it can be easily processed out of the images though.

[t00fri]

This one I find quite intriguing: look at the strange 3d appearance of the bright "stuff" .

Bye Fridger

[maxim]

That looks like edge enhancing artifacts to me.

maxim

[Dollan]

These features actually look, to me, very wind-eroded. It could be a trick of the eye, attempting to link different features together, but I seem to see linear patterns, like rock etched by the wind, and leaving streaks of tailing behind.

Or, conversely, I could be suffering from lack of sleep!

...John...

[Matt McIrvin]

I'm reminded of Triton by these pictures. No cantaloupe terrain, but there are those dark spots/streaks on the lighter areas. Aren't Triton and Titan pretty much identical, other than the obvious size and atmospheric differences?

The light areas look Triton-esque to me, too, but it's so blurry that it's hard to tell. There might even be cantaloupe terrain down there. The haze keeps light and shadow from revealing surface relief. There are both bright and dark linear features that might be ridges or canyons or both.

Triton's colder than Titan, considerably smaller (a little over half as large as Titan in diameter), and obviously has a much thinner atmosphere.

[Evil Dr Ganymede]

Erm. Bwuh!! Finally, a clear view!!

http://photojournal.jpl.nasa.gov/catalog/PIA06982

(the caption's wrong - the piccie on the right is from VIMS (Visual Infared Mapping Spectrometer, I think), the picture on the left is what the imaging camera sees). Helluva difference huh? I bet they'll be scrabbling to change the imaging sequences for next time, and bringing VIMS to the fore instead of ISS (Imaging Science System, or what's been taking the images so far).

And it kinda reminds me of this image, which is a view of a region on Ganymede. I'd swear those striations in the dark terrain on Titan are reminiscent of the "grooves" on Ganymede...!

Or maybe I'm wishful thinking

[t00fri]

Erm. Bwuh!! Finally, a clear view!!

http://photojournal.jpl.nasa.gov/catalog/PIA06982

(the caption's wrong - the piccie on the right is from VIMS (Visual Infared Mapping Spectrometer, I think), the picture on the left is what the imaging camera sees). Helluva difference huh? I bet they'll be scrabbling to change the imaging sequences for next time, and bringing VIMS to the fore instead of ISS (Imaging Science System, or what's been taking the images so far).

And it kinda reminds me of this image, which is a view of a region on Ganymede. I'd swear those striations in the dark terrain on Titan are reminiscent of the "grooves" on Ganymede...!

Or maybe I'm wishful thinking

Wow,



First of all, this shows clearly, that both the bright and dark areas are solid! Or more specifically, that the dark ones are not liquid. Also there is little doubt about a terrasse-type structure of the bright material.

Moreover, if I interpret the left image correctly ("visual" ~ digital camera) , this means that from an altitude of ~1200 km, i.e. from above the major part of the atmosphere, I can still make out schematic features of the surface visually, as long I am sufficiently close!?

Turned around, this seems to be evidence that an observer standing on Titan's surface should roughly see where the sun is!

Bye Fridger

[Evil Dr Ganymede]

Yeah. It doesn't look like there are oceans there, does it (at least in that locale on the surface anyway).

The left image shows that you can't see bugger all on the surface even when you're really close and you're looking using the 2 micron wavelength. You can differentiate between bright and dark but that's it, which isn't hugely useful.

[t00fri]

Yeah. It doesn't look like there are oceans there, does it (at least in that locale on the surface anyway).

The left image shows that you can't see bugger all on the surface even when you're really close and you're looking using the 2 micron wavelength. You can differentiate between bright and dark but that's it, which isn't hugely useful.

Reading the caption again carefully, it seems they only mixed up left and right. Both pictures where taken with the visual & IR spectrometer (VIMS). The visible acceptance extends from 0.35 -- 1.07 micron, while the IR acceptance ranges between 0.85 -- 5.1 micron in this instrument. Deep IR observations are handled by the CIRS instrument (7 -- 1000 micron).

Thus the "sharp" picture was said to be centered around 2 microns, i.e. in the bona fide IR regime. The fuzzy one around 1 micron with a substantial tail into the visual (cf the comparison with a "digital camera" view) but apparently NOT covering the first IR window, located somewhat above 1 micron. The sensitivity of digital cameras is known to cover a larger range of wavelengths than the eye...anyway, the fuzzy image does seem useful to me, cf my remark above...

Bye Fridger

[ArneB]

How can you tell form these images that the dark feature isn't a ocean? I'm not saying that it is, but the picture is kind of blurry, and more important, why would an icecold hydrocarbon ocean have a coastline that exactly resembles that of a water ocean? Personally, I think the terrasse-"islands" look like ice that's drifting around in a sea, and the features that give them the terrasse-look are borders between ice flakes.

I may be very wrong here, but shouldn't the conditions on Titan be perfect for the creation of hydrate ice (high pressure, low temperature and a lot of hydrocarbone), like the kind that clogs oil pipes?

by the way, are we still waiting for the radar images?

[t00fri]

""

[t00fri]

ArneB,

you are correct that no-one at present can exclude that
some parts of the dark areas seen on Titan are or contain liquid.

You should consider, however, that the images you show
above have been taken from a quite far distance of 340000 Km!

In contrast, I was specifically referring above to the
closest Titan photo so far (cf my colorized image).

It was taken at only 1200 km distance!

There you clearly can see grooves in the black terrain,
which is a manifest sign of its solid composition.

So it does not make much sense to argue with images
taken from 340000 Km distance against images taken at
only 1200 Km distance. What do you think? You could
never make out the grooves (that I took as evidence)
from your images above...

Bye Fridger

[ArneB]

I see what you mean, but do the streaks need to be groves? It may be groves in subsurface ice/other material that shows through the liquid, or it might be melting material of a slightly different colour that is drifting away from the ice.
I don't mean to quarrel, it is just so annying to give up the idea of the Huygens probe returning the first images ever of an ocean on another world.

[t00fri]

I see what you mean, but do the streaks need to be groves? It may be groves in subsurface ice/other material that shows through the liquid, or it might be melting material of a slightly different colour that is drifting away from the ice.
I don't mean to quarrel, it is just so annying to give up the idea of the Huygens probe returning the first images ever of an ocean on another world.

I understand that one expects lakes/oceans composed of
hydrocarbons if any. The freezing point of those is pretty
low, I gather...

But once more: there may be other black areas with
precisely such liquid hydrocarbon lakes. The
close-distance flyby images only cover a very small field
of view.

My point was simply that the images you presented
above were useless in the context of the evidence I
discussed further above, since they were taken from too
far away.

Bye Fridger

[Brendan]

Could some of the dark stuff on Titan be like the dark stuff on Iapetus?

Brendan

[Ynjevi]

I hope the radar image taken by Cassini will be released soon. It was displayed in today's news conference.

There are visible some dark (radar dark, i.e. very smooth) areas that could be liquid on the surface. There are also some evidence of (icy) volcanism (features similar to the Magellan Venus images), and lack of craters indicate that the surface is young.

Overally the imaged area (100s of kms) is very flat, height difference is only 15 meters or so.

Temperature mapping (?) indicates that the surface is mostly covered by organic materials instead of hard ice.

[Ynjevi]

Could some of the dark stuff on Titan be like the dark stuff on Iapetus?

It has been speculated that the dark material on Iapetus may have been originated from Titan, but if it is the case, it doesn't have to originate from the dark areas.

Unless I'm terribly wrong, the surface of Titan has not very large brightness variations, the great difference between light and dark areas has been stretched. The surface has been imaged only in infrared wavelengths, so we don't know how it would look like if it was viewed in visible light. Plus, although initially after the first distant Cassini flyby dark areas were tought to be relatively pure ice (and before that, vice versa...) it now seems to be somewhat similar to the light material in composition. But we really don't know yet.

[Ynjevi]

There are visible some dark (radar dark, i.e. very smooth) areas that could be liquid on the surface.

'Black Cat' on Titan.

[Evil Dr Ganymede]

Dammit, I wish they had some visual context with the radar image... (and I wish they had a bigger radar image to pore over). Looks interesting...



I see nothing there that unamibiguously looks like it could be liquid - in fact, it looks similar to the radar images of the volcanic plains on Venus. At this stage I'd say we're looking at a relatively smooth plain. The bright patches could be a rougher region, the darker regions could just been smoother than the surroundings...

More and more mysteries...