NASA | JPL-Caltech | Cassini | 2016 Aug 10
[c][attachment=0]main_titan_flooded_canyons[1].gif[/attachment][/c][hr][/hr]NASA's Cassini spacecraft has found deep, steep-sided canyons on Saturn's moon Titan that are flooded with liquid hydrocarbons. The finding represents the first direct evidence of the presence of liquid-filled channels on Titan, as well as the first observation of canyons hundreds of meters deep.
A new paper in the journal Geophysical Research Letters describes how scientists analyzed Cassini data from a close pass the spacecraft made over Titan in May 2013. During the flyby, Cassini's radar instrument focused on channels that branch out from the large, northern sea Ligeia Mare.
The Cassini observations reveal that the channels -- in particular, a network of them named Vid Flumina -- are narrow canyons, generally less than half a mile (a bit less than a kilometer) wide, with slopes steeper than 40 degrees. The canyons also are quite deep -- those measured are 790 to 1,870 feet (240 to 570 meters) from top to bottom.
The branching channels appear dark in radar images, much like Titan's methane-rich seas. This suggested to scientists that the channels might also be filled with liquid, but a direct detection had not been made until now. Previously it wasn't clear if the dark material was liquid or merely saturated sediment -- which at Titan's frigid temperatures would be made of ice, not rock. ...
Methane-Filled Canyons Line Titan's Surface
American Geophysical Union | 2016 Aug 10
Liquid-filled Canyons on Titan - Valerio Poggiali et al
- Geophysical Research Letters (online 09 Aug 2016) DOI: 10.1002/2016GL069679