Best case scenario would probably be in October, either right before T19, the next major SAR pass, or in the second week of October for the DPS meeting (which I may or may not be at, it's still up in the air). The latest you would see the whole thing would be in early July of next year when it is released on to the PDS.

Did you get paid? I think I got a fully-fledged piece of the bet...

Have you seen the whole radar swath? Anything else in it catch your eye or did they already release the interesting bits?

Yep. I think I will frame the check instead, though, not sure yet.


Yes.

........... to what? lol

Has anyone estimated the illumination levels on Titans surface during day/night? Has the Huygens probe measured this directly?

Typically, for earth conditions, the following levels are typical:

Twilight - 4 lux
Full Moon - 0.2 lux
No Moon - 0.001 lux

There is some information about daylight illumination levels on Titan’s surface in one of the Huygens’ Papers, released last December (Tomasko et al., 2005)

“The brightness of the surface of Titan is about a thousand times dimmer than full solar illumination on the Earth (or 500 times brighter than illumination by full moonlight). That is, the illumination level is about that experienced about 10 min after sunset on the Earth. The colour of the sky and the scene on Titan is rather orange due to the much greater attenuation of blue light by Titan's haze relative to red light. If the Sun is high in the sky, it is visible as a small, bright spot, ten times smaller than the solar disk seen from Earth, comparable in size and brightness to a car headlight seen from about 150 m away. The Sun casts sharp shadows, but of low contrast, because some 90% of the illumination comes from the sky. If the Sun is low in the sky, it is not visible.”

During the night, it will probably be quite dark at the Huygens Landing Site, since this place it on the anti-saturnian hemisphere of Titan.

Concerning the T16 RADAR Swath: I am also anxious to know if there are some really striking parts left to be released, but I guess patience is mandatory here.

I wonder how long twilight lasts on Titan? On Earth, astronimical twilight lasts for about 1.5 hours, or 22 degrees longitude. On Titan, I might expect twilight to last longer since the atmosphere is thicker and deeper (relative to the radius), but it may be "dimmer" since the atmosphere is more opaque.

--Bill

I'm surprised to see the progression/extent of twilight talked about as a singular thing. It surely varies with season, latitude, and sky conditions. At equinox on the equator, the Sun plunges perpendicularly to the horizon, dropping 15 degree per hour. At midlatitudes, it typically slices at a 45ish-degree angle, and so proceeds below the horizon at about 70% that rate. US/Europe travelers to the tropics may be shocked at how quickly sunset leads to darkness. Of course, in the polar long seasons, even when the Sun does set, it doesn't get very far below the horizon.

Even in "clear" weather, humidity and dust can soften/mute the light/dark distinction: humid air 15 km overhead can still "see" the Sun about 20 minutes after sunset, while the air over the western horizon roughly doubles that. But subtract the humidity and the effect becomes much less relevant.

In a nutshell, I think the residents of Oslo and Tuscon have a very different experience at twilight.

More importantly, Titan turns on its axis only once every 16 days.

Bill's question is interesting. As he refers to degrees of longitude I'm sure he means how long is twilight as a fraction of the day length. Or (to eliminate the latitude issue) - How far below the horizon does the Sun have to be for complete darkness on Titan? I too would expect the answer to be greater than the corresponding value for Earth because the ratio of atmospheric scale height to radius is approximately 6 times greater for Titan. (For the very distended outer layers of Titan's atmosphere the scale height is 2.5 times greater still, but I'm not sure how much twilight this very tenuous part of the atmosphere would contribute.) In the case of an arbitrarily small small globe with a very extended atmsphere there would of course be twilight all 'night'.

Anybody know anything about T17 yet?

It sounds like one of the closest flybys so far at 1,000 km.

Apologies if this has been posted before, but there’s are quite recent (8/29/2006) CHARM presentation on Titan (http://saturn.jpl.nasa.gov/multimedia/products/pdfs/20060829_CHARM_Soderblom.pdf). What I found interesting is the plethora of question marks after the arctic “ethane/methane lakes” detected during T16 (see the last pages of the presentation). They have sound a lot more confident in the latest press release (http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=679).