Titan's changing lakes Options

[Jason W Barnes]

The VIMS team has published a short paper in GRL on their specular reflection observation:

Stephan, K., R. Jaumann, R. H. Brown, J. M. Soderblom, L. A. Soderblom, J. W. Barnes, C. Sotin, C. A. Griffith, R. L. Kirk, K. H. Baines, B. J. Buratti, R. N. Clark, D. M. Lytle, R. M. Nelson, and P. D. Nicholson (2010),
Specular reflection on Titan: Liquids in Kraken Mare,
Geophys. Res. Lett., doi:10.1029/2009GL042312, in press.

Link to the paper on my site.

I hadn't realized it was out in the "papers in print" yet even! Good eye ISS Jason . . .

- VIMS Jason

[volcanopele]

no problem. Though it does remind me that I should make some graphics showing the geography around Kraken Mare for the workshop next week

Great work VIMS Jason and the rest of the VIMS group!

[titanicrivers]

Very nice paper! Thanks for posting here Jason. There’s also an ASC 2010 meeting abstract with many of the same authors and some additional location maps. http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5149.pdf. In that abstract
there’s a location map (Fig 2) that shows the probable glint source locations. The strongest glint appears to be pretty much the same area just ‘off shore’ from the + sign in this estimate from post # 145 shown below. Whether this is a bay of Kraken Mare or a separate unnamed large lake (unofficially referred to as Sunglint Lake) remains speculative.

[Jason W Barnes]

Very nice paper! Thanks for posting here Jason. There’s also an ASC 2010 meeting abstract with many of the same authors and some additional location maps. http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5149.pdf. In that abstract
there’s a location map (Fig 2) that shows the probable glint source locations. The strongest glint appears to be pretty much the same area just ‘off shore’ from the + sign in this estimate from post # 145 shown below. Whether this is a bay of Kraken Mare or a separate unnamed large lake (unofficially referred to as Sunglint Lake) remains speculative.

We've got a name request in for the sunglint lake. I'll don't want to leak the requested name, but I'll let you know when it's been approved.

- VIMS Jason

[Jason W Barnes]

Your RADAR map is incomplete, I think. Take a look at the RADAR T30 S02 data in the PDS -- it extends the strip to show the SE corner of sunglint lake. Makes a pretty good case that the lake is separate, but still not 100% for sure.

- VIMS Jason

[titanicrivers]

Your RADAR map is incomplete, I think. Take a look at the RADAR T30 S02 data in the PDS -- it extends the strip to show the SE corner of sunglint lake. Makes a pretty good case that the lake is separate, but still not 100% for sure.

- VIMS Jason

I realized that when I looked at Figure 2 in the ASC 2010 meeting abstract http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5149.pdf. Fig 2a shows the same radar swaths (as they appeared in VP's polar maps that I used) however Fig2b shows the extension of radar swaths to fill in the SE portion of Sunglint Lake as you point out above.
BTW: I didn't find the same glint mapping figures in your post of the paper as appeared in the ASC abstract, yet it seemed your paper was referring to such in the body of the text. Perhaps my browser didn't download that Figure properly from your paper.

[volcanopele]

no problem. Though it does remind me that I should make some graphics showing the geography around Kraken Mare for the workshop next week

Hmm, not sure why I kept thinking that the TSWG workshop is next week... regardless, I should try to print out some of my cartographic products (at least to remind people yes, we see the surface, no it's as colorful as what VIMS can see, but it can still look cool... and shows distinct boundaries of features before RADAR can see them ;-)

[hendric]

Dumb Q, but could Cassini detect specular reflections of Saturn in the lakes? Or is it too "faint" in comparison to the sun to be visible?

[Jason W Barnes]

Dumb Q, but could Cassini detect specular reflections of Saturn in the lakes? Or is it too "faint" in comparison to the sun to be visible?

Interesting idea. I haven't thought about it before. My guess is that it wouldn't be a very impressive observation, but I should do the calculation.

- VIMS Jason

[hendric]

If there is one, perhaps you could use it to monitor the evaporation of liquids from the dark pole? Saturn's brightness won't change significantly over the course of the XXM.

[ngunn]

This sounds like a great idea to me. It would have to be a nightside image though, so the sooner the better. With most of the lakes being in the north plus darkness retreating from high northern latitudes and the huge amount of scattering that occurs in Titan's atmosphere spreading twilight so far around the globe the chances may already be slender. There's always Ontario, of course.

[Hungry4info]

What could we learn from such an observation that seeing the reflection of the sun itself wouldn't?

[hendric]

Well, Saturn is much larger in the sky than the sun from Titan's surface, so the odds of a reflection are much higher. If it is possible to do multiple targettings over the XXM then we could see if the reflection profile changes brightness or color.

I don't think it could be done during a night pass, because of the geometry. I think the best bet is to try during a half-full Saturn phase as viewed from Titan. That alone might make it unlikely, because of the brightness of the rest of the planet in daylight.

[rlorenz]

Well, Saturn is much larger in the sky......That alone might make it unlikely, because of the brightness of the rest of the planet in daylight.

And whatever the geometry, the light is down by a factor of (1/20)^2 = 400 since
Saturn's light is spread over a sphere equal to Titan's radius. Pulling that signal out
from the scattered light in Titan's atmosphere could be a challenge.

Now if only there were some way of illuminating the surface any time you wanted, with
some, like, 'magic' light that wasnt scattered by the atmosphere..... oh, wait...

[volcanopele]

We've got a name request in for the sunglint lake. I'll don't want to leak the requested name, but I'll let you know when it's been approved.

- VIMS Jason

The name has been approved. The sunglint lake is now known as Jingpo Lacus, after a lake in China.

Coincidently (or not actually, it was quite intentional...), Jingpo Lacus means "Mirror Lake"

http://en.wikipedia.org/wiki/Jingpo_Lake