This near-infrared, color mosaic from NASA's Cassini spacecraft shows the sun
glinting off of Titan's north polar seas. While Cassini has captured,
separately, views of the polar seas (see PIA17470) and the
sun glinting off of them (see PIA12481 and PIA18433) in the
past, this is the first time both have been seen together in the same view.
The sunglint, also called a specular reflection, is the bright area near the
11 o'clock position at upper left. This mirror-like reflection, known as the
specular point, is in the south of Titan's largest sea, Kraken Mare, just north
of an island archipelago separating two separate parts of the sea.
This particular sunglint was so bright as to saturate the detector of
Cassini's Visual and Infrared Mapping Spectrometer (VIMS) instrument, which
captures the view. It is also the sunglint seen with the highest observation
elevation so far -- the sun was a full 40 degrees above the horizon as seen from
Kraken Mare at this time -- much higher than the 22 degrees seen in PIA18433. Because
it was so bright, this glint was visible through the haze at much lower
wavelengths than before, down to 1.3 microns.
The southern portion of Kraken Mare (the area surrounding the specular
feature toward upper left) displays a "bathtub ring" -- a bright margin of
evaporate deposits -- which indicates that the sea was larger at some point in
the past and has become smaller due to evaporation. The deposits are material
left behind after the methane & ethane liquid evaporates, somewhat akin to
the saline crust on a salt flat.
The highest resolution data from this flyby -- the area seen immediately to
the right of the sunglint -- cover the labyrinth of channels that connect Kraken
Mare to another large sea, Ligeia Mare. Ligeia Mare itself is partially covered
in its northern reaches by a bright, arrow-shaped complex of clouds. The clouds
are made of liquid methane droplets, and could be actively refilling the lakes
with rainfall.
The view was acquired during Cassini's August 21, 2014, flyby of Titan, also
referred to as "T104" by the Cassini team.
The view contains real color information, although it is not the natural
color the human eye would see. Here, red in the image corresponds to 5.0
microns, green to 2.0 microns, and blue to 1.3 microns. These wavelengths
correspond to atmospheric windows through which Titan's surface is visible. The
unaided human eye would see nothing but haze, as in PIA12528.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. JPL, a division of the California
Institute of Technology, Pasadena, manages the mission for NASA's Science
Mission Directorate in Washington. The VIMS team is based at the University of
Arizona in Tucson.
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