[X] My Assistant

[Juramike]

Liquid Lakes confirmed on Titan!

Latest issue of Nature provides evidence that Ontario Lacus at Titan's South pole is definitely liquid.

Space.com article: http://www.space.com/scienceastronomy/080730-titan-lake.html

-Mike

[ngunn]

OK here goes. Using polarisation of reflected skylight to study Titan's lakes is of course up against the ever-present problem of scattering by the atmospheric haze. This gets worse at oblique angles, so first I ask:

Q1 - What is our best estimate for the Brewster angle for Titan's lakes at VIMS and ISS wavelengths?

Whatever the optimum viewing angle it's certain that only a small fraction of the photons reflected by a lake make it out through the haze unscattered. Hence it is necessary to ask also:

Q2 - how much does forward scattering by the haze mess with the plane of polarisation? (Rather a lot would be my guess.)

And:

Q3 - Is the small fraction of unscattered photons sufficient to yield observable contrast between lake images taken with different polarising filters? (My guess again: slight but maybe just observable. Certainly not like the college pond pictures!)

If the answers to all three questions leave any grounds for optimism then the potential prize could be great: processed images of lakes (or at least shiny areas) produced selectively from unscattered photons. This could potentially increase the resolution of shoreline features well beyond what the infrared instruments (ISS especially) are able to achieve at Titan by other means.

Q4 - Does any of this make sense?