"TAU researcher confirms oily "water" on a Saturn moon", so reads the email that crossed my desk.  Then I learned why no mountain or landform on Titan can ever be taller than 6,200 feet.  The reason surprised me, but first, the backstory about the paper.

The Cassini-Huygens mission to Saturn has generated many exciting discoveries about the planet and its moons - and now a Tel Aviv University (TAU) researcher associated with the project has determined that Saturn's moon Titan includes a unique population of lakes.

Prof. Akiva Bar-Nun of Tel Aviv University says that, instead of water, the lakes of Titan are composed of liquid ethane and methane, not unlike those found in Earth's oil and gas wells. In the form of rain, this methane and ethane fall upon the surface of the planet, forming large pools - "but you wouldn't want to jump into them on a summer holiday," he cautions.

The full paper is in the reputable Journal of Geophysical Research - Planets.  TAU also notes that "Prof. Bar-Nun says that these recent findings confirm predictions that he made in 1979".  As always, the best science, bar none, is that which confirms a prediction made before the measurements were taken.  It's easy to theorize after the fact, much harder to predict, but only prediction gives science its power.

Back to why there's a height limit on Titan.  Titan ice, they claim, is like permafrost, and thus partially fluid.  So it can't maintain its shape against gravity if it's too tall.  For this and other neat conclusions, feel free to check the original source.

See you next week,
Alex
Tuesdays at The Satellite Diaries and Friday at The Daytime Astronomer (twitter @skyday)