Notice the thin "channel" like feature coming out of the large dark area on the left?

we've noticed quite a few river-like channels...

Could that circular feature be a crater?

This image looks like it has 2:
Link

Here is another... remember that these are from raw images, without any enhancement whatsoever on my part. I have to think that the images of Titan will be much more informative once they have been properly processed.

It does look like there are quite a few of these 'river-like' features on Titan.

Bill

Here is another 'river-like' feature, this one winding its way across the image. The contrast is rather low, but it is still visible on the raw image.

Bill

Jason,

Are you seeing any more details aside from those channels? Any signs of craters? Are you disappointed with the pictures? Do you expect better results from the radar?

And WHAT is this?! clouds? mountains?

http://saturn.jpl.nasa.gov/multimedia/imag...feiImageID=6979

also nice:

http://saturn.jpl.nasa.gov/multimedia/imag...feiImageID=6913

When is the press conference?

Any ideas what kind of image processing is applied to the images to extract the most amount of imformation from them? JPL have already released a crude map of Titan taken from several million km's away that show surface features, the corresponding RAW images dont show any at all though. Unlike this latest batch.

Adjusted the contrast on this image, the darker features stand out a bit better now.

To Pioneer: those circular features are, alas, just circular shadows cast by dust specks on the camera -- an annoyance that turns up very often on spacecraft photos and has to be edited out.

However, Sunspot's cranked-up contrast version is fascinating -- I'm going to have to eat certain nasty words I have been uttering today about the near-total uselessness of these pictures. These DO look like flows of something, either flat-out liquid or at least viscous.

Did you see the mosaic of images of Titan they released at yesterdays press briefing? They were taken from a distance of several million kilometres:

http://photojournal.jpl.nasa.gov/catalog/PIA06086

How they managed to pull out that much detail from that distance is quite amazing, I couldnt see any features at all in the RAW images.

So it should be very interesting to see what they extract from these close up RAW images.

Thanks, that map is my baby I guess., I worked on that for three weeks.

The main enhancement done, and the ones that will be shown tommorrow was a lunar-lambert photomentric correction. Not perfect, but good enough for the time being.

tomorrow? I didn't see it on the NASA-TV schedule. When is it?

Its on the JPL homepage http://www.jpl.nasa.gov/index.cfm

10am PDT / 5pm GMT I think, 6pm UK time

Great! thanks a lot for the info

heres another pic:

Not surea bout the scale, but here's the info for the picture:

N00006570.jpg was taken on July 02, 2004 and received on Earth July 02, 2004. The camera was pointing toward TITAN at approximately 339,001 kilometers away, and the image was taken using the IRP0 and CB3 filters.

do you know what the scale is?

or do i see the horizon down below?
If that is the case these are massive "flows". Maybe its something like Valles Marineres...

Very curious what the experts have to say

To me it looks like large clouds over something

Doug

if we know the angle of the NAC then we know the scale

http://saturn.jpl.nasa.gov/spacecraft/inst...iss-details.cfm

ISS Sensing Instruments:

* Wide Angle Camera [WAC](20 cm f/3.5 refractor; 380-1100 nm; 18 filters; 3.5ox3.5o)
* Narrow Angle Camera [NAC](2 m f/10.5 reflector; 200-1100 nm; 24 filters; 0.35ox0.35o)

I hope not lol

scale is 2.02 km/pixel. As far as what the experts think, I'll hold off on my speculations till after i hear what was in the press conference. I can't view it right now. but I will give you this thought, ice cream.

Interesting. Dark areas seem to be pure water ice while the brighter areas seem to be mixed in with hydrocarbons. I wonder if they're seeing any signs of liquid hydrocarbons. And that really bright feature near the South Pole turns out to be a cloud.

I am less than convinced that the dark areas are more-or-less pure water ice. Remember that this hypothesis had just been suggested a few hours before the press conference was held, and could not have been thoroughly analysed in the time available.

Why I doubt this idea:

1) The hypothesis is based almost entirely on the 2.8 micron band image of the surface of Titan, which shows almost the entire surface of Titan (other than a few clouds near the south pole) being quite dark, which is consistent with the surface having a large percentage of water ice.

However, liquid methane (at 93 degrees Kelvon) also absorbs infrared light at 2.8 microns (see attached plot). The amount of absorption is sufficient that more than a few metres depth of liquid methane should appear quite dark. I have also looked for an infrared spectrum of liquid ethane at 90-95 degrees Kelvin, that covers 2.8 microns, but cannot find one on the Web. They all stop at 2.5 microns. If anybody knows the infrared absorption of liquid ethane at 2.8 microns, it would help decide this issue one way or the other.

2) The other support for this theory is the absence of specular reflections. If the sun had been in the correct position, these should have been visible in the returned images.

On the other hand, Earth-based radar imaging of Titan does show 'glints' that suggest specular reflections. Also, the area imaged in this flyby was one of the most dark-area-free portions of Titan's surface, according to the near-global map released recently. A specular reflection requires that the spot which would reflect the image of the sun be covered by a body of liquid, but almost all the area of Titan visible in this flyby was light-colored 'land', not dark-covered 'sea', so the probability of seeing a specular reflection--even if the dark areas are in fact 'seas'--is actually quite low.

3) There are a number of dark, 'river-like' features visible in the images, which appear to drain into the dark areas. These are most simply explained as being liquid-methane+ethane rivers, or their surrounding river valleys.

4) The atmosphere of Titan is most simply explained by assuming that open bodies of methane+ethane lie on the surface of Titan, with the atmosphere in equilibrium with them, plus the effects of solar UV.

Bill

Yes, there are quite a few fine sinuous features visible in the images. here are my attempts at bringing out a bit more detail.



This is a full size crop of the image above:



One more

While looking at the Titan mosaic, I noticed what appears to be an escarpment running along much of the length of the image. There is a clear difference in the albedo and texture of the surface on either side of this 'escarpment'. It looks to me that this 'escarpment' marks one edge of an extensive geologic/topographic unit, which can be delineated over much of the visible surface.

Attached is my outline of this unit. Does this look real to anybody else, or am I imagining it?

Bill

I certainly see the bottom half of what you're seing. It might be an altitude related thing - like the geologic version of a tree line perhaps? As to if it's going down in the middle, or up in the middle - well, bring on the radar

Doug

It's in the right spot to be a polar cap. (the bottom half)

What would a polar cap look like on Titan? What would freeze?

The average temperature at the surface of Titan is, according to current atmospheric models, 95 degrees Kelvin. Methane, at one atmosphere pressure (the surface of Titan is at 1.6 atmospheres pressure, according to current models), freezes at 90.4 degrees Kelvin, or 96.2% of the average temperature. The freezing point would be slightly higher at 1.6 atmospheres pressure, but not a lot higher (maybe a few tenths of a degree).

For comparison, the 1940-1980 average temperature of the Earth was 288 degrees Kelvin, while water, at one atmosphere pressure, freezes at 273 degrees Kelvin, or 94.8% of the average temperature.

So, if there are 'ice caps' on Titan, they are likely to be primarily composed of methane.

Bill

No Lakes on Titan? Too Soon to Tell

http://www.planetory.org/news/2004/cassini...sults_0706.html