Ligeia Mare from a false-color mosaic of synthetic aperture radar images of Titan's north polar region.
Ligeia Mare / / is a lake in the north polar region of Titan, the planet Saturn's largest moon. It is the second largest known body of liquid on Titan, after Kraken Mare. Larger than Lake Superior on Earth, it is composed of liquid hydrocarbons (mainly methane and ethane). It is located at 78° N, 249° W, and has been fully imaged by the Cassini spacecraft. It measures roughly 420 km (260 mi) by 350 (217 mi) km across, has a surface area of about 126,000 km2, and a shoreline over 2000 km (1240 mi) in length. Its namesake is Ligeia, one of the sirens in Greek mythology.
Ligeia Mare has two predominant types of coastline, "crenulated" and "subdued". The former is characterized by hummocky, eroded terrain, the latter by lower, smoother topography and the presence of more numerous and longer channels. Crenulated terrain predominates on the eastern and southern sides of the lake; subdued terrain to the west and north. Except in the southeast where the rough topography extends to the coast, hummocky terrain tends to be separated from the shoreline by a more subdued bench. The coast has numerous bays that appear to be flooded river mouths (rias), and unlike at Ontario Lacus there are no visible subaerial delta deposits, possible evidence of a recent sea level rise. In the northeast and northwest sections of the mare, along about a quarter of the total shoreline, there are extensive areas where the depth is less than 5 m, shallow enough for imaging radar to penetrate to the bottom.
The shorelines of Ligeia Mare and other north polar lakes and maria have been stable over the period of observation by Cassini, in contrast to south polar Ontario Lacus, where there has been significant shoreline recession.
Ligeia Mare is the primary target for the Titan Mare Explorer, a proposed lander mission which would splash down on and then drift about the lake. The Titan Lake In-situ Sampling Propelled Explorer (TALISE) is another proposed lander mission which would splash down and navigate across the lake, the major difference between the TiME and TALISE space probes would be a propulsion system.
Comparison of Ligeia Mare's size with that of Lake Superior on Earth
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