Titan Has Eight Low Albedo Features That Darken Its Surface

Summary: Titan has eight low albedo features that darken its surface, with seven centered in the equatorial belt and one centered outside the equatorial belt.

Detail of Titan VIMS (Visual and Infrared Mapping Spectrometer) Map shows dark albedo features of Fensal-Aztlan and Aaru-Senkyo as occupants of opposite sides of prime meridian on Titan's Saturn-facing side; map credit NASA/JPL/University of Arizona: No known copyright restrictions, via IAU-USGS Astrogeology Science Center's Gazetteer of Planetary Nomenclature

Titan has eight low albedo features that darken its surface, with two centered in the northern equatorial belt, five centered in the southern equatorial belt and one centered outside the southern equatorial belt.

The low reflectivity of Titan's eight named dark albedo features blacken the surface of Saturn's largest moon. Aaru, Aztlan, Belet, Ching-Tu, Fensal, Mezzoramia, Senkyo and Shangri-La are the eight named albedo features that nighten Titan's surface. Seven of the eight low albedo features are centered in the equatorial belt. Only Mezzoramia is centered outside of the equatorial belt.

Titan's planetographic coordinate system measures longitude in degrees west of the prime meridian, set at 0 degrees longitude. Shangri-La, Ching-Tu, Belet, Aaru and Senkyo lie in progressively higher longitudes westward in the equatorial belt from the cluster of prime meridian neighbors Aztlan and Fensal. Mezzoramia's longitudinal centering on the prime meridian and latitudinal placement in the south polar region, far south of Titan's southern equatorial latitudes, establish its southern distance from the other seven.

Aaru shares the far western equatorial belt with near southern neighbor Senkyo. Belet lies to Aaru's east. Mezzoramia is located distantly to the south.

Aaru is centered at 10 degrees north latitude, 340 degrees west longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern equatorial belt-centered dark albedo feature's center coordinates are repeated as its northernmost and southernmost latitudes and easternmost and westernmost longitudes. Aaru's diameter, listed as zero, is likewise unspecified.

Aaru numbers as one of five dark albedo features centered on or in proximity to the prime meridian. Aaru's high western longitudinal centering nears the prime meridian by 20 degrees.

Aztlan associates with Fensal as its northern neighbor. Mezzoramia lies distantly to the south.

Aztlan is centered at minus 10 degrees south latitude, 20 degrees west longitude. The southern equatorial belt-centered low albedo feature's incomplete Gazetteer profile identifies its center coordinates as its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Also, Aztlan's diameter is placed at zero.

Aztlan members in the quintet of dark albedo features located in proximity to the prime meridian. Only 20 degrees separate Aztlan's center longitude from the prime meridian.

Belet is located between Aaru and Sankyo, to the west, and Shangri-La, to the east. Ching-Tu neighbors to the southeast of Belet.

Belet is centered at minus 5 degrees south latitude, 255 degrees west longitude. The southern equatorial belt-centered dark albedo feature's center coordinates are given for its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Its diameter is given as zero.

Ching-Tu's neighborhood occurs to the east of the Aaru-Sankyo cluster. Ching-Tu's downward arc tags Belet to the northwest and Shangri-La to the northeast.

Ching-Tu is centered at 30 degrees south latitude, 205 degrees west longitude. The Gazetteer's profile for the southern equatorial belt-centered dark albedo feature is incomplete, with Ching-Tu's northernmost-southernmost latitudes and easternmost-westernmost longitudes repeating its center coordinates. Its diameter is listed as zero.

Ching-Tu's center latitude places it at the edge of the southern equatorial belt. Its location on the equator's southernmost latitude qualifies it as the dark albedo feature with the southernmost equatorial centering.

Fensal associates with southern neighbor Aztlan. The Fensal-Aztlan cluster is known as Titan's "H region" because of the lowercase letter h that they appear to form, according to NASA Jet Propulsion Laboratory's (JPL) Photojournal website's post, "Monitoring 'Fensal-Aztlan,'" published Sep. 13, 2005.

Fensal is centered at 5 degrees north latitude, 30 degrees west longitude. The Gazetteer's incomplete profile for the northern equatorial belt-centered low albedo feature repeats its center coordinates as its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Zero is given as its diameter.

Fensal belongs to the quintet of dark albedo features positioned near or on the prime meridian. Fensal's center longitude lies in 30-degree nearness to 0 degrees of longitude.

Mezzoramia is positioned in remote isolation from Titan's seven other low albedo features. The southern middle latitudes intervene between Mezzoramia and the other seven, all centered in the equatorial belt.

Mezzoramia is centered at minus 70 degrees south latitude, 0 degrees longitude. The prime meridian-centered dark albedo feature's center coordinates are identified as its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Mezzoramia's diameter is placed at zero.

Mezzoramia distinguishes itself latitudinally and longitudinally. Its center latitude of 70 degrees south, in the southern hemisphere's polar region, excludes Mezzoramia from the equatorial belt centering that characterizes Titan's seven other low albedo features. Mezzoramia's longitudinal centering at 0 degrees longitude qualifies it as the only one of Titan's eight named dark albedo features that is centered on the prime meridian.

Senkyo associates with northern dark neighbor Aaru. The Aaru-Senkyo and Aztlan-Fensal clusters find themselves on opposite sides of the prime meridian.

Senkyo is centered at minus 5 degrees south latitude, 320 degrees west longitude. The southern equatorial belt-centered dark albedo feature's center coordinates are repeated for its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Senkyo's diameter is listed as zero.

Senkyo participates in the five-member group of prime meridian-associated dark albedo features. Only 40 degrees separate Senkyo's center longitude from the prime meridian.

Shangri-La assumes almost a midway position in the equatorial belt. It neighbors with Ching-Tu to the southwest and Belet to the west.

Shangri-La is centered at minus 10 degrees south latitude, 165 degrees west longitude. The southern equatorial belt-centered low albedo feature's center coordinates are entered for its northernmost-southernmost latitudes and easternmost-westernmost longitudes. Shangri-La's diameter is given as zero.

Titan's prime meridian bisects the Saturnian moon's Saturn-facing hemisphere. Equal-length orbital and rotational periods cause Titan to show the same side to Saturn. The half circle of Titan's anti-meridian, measured at 180 degrees west longitude, bisects the moon's anti-Saturn, or far, side in its formation of a full circle with the prime meridian.

Five of Titan's eight dark albedo features are found on Titan's Saturn-facing, or near, side. The clusters of Aaru-Senkyo and Aztlan-Fensal join distantly southern Mezzoramia on Titan's Saturn-facing side.

Three of Titan's eight low albedo features are located on Titan's anti-Saturn side. The trio of Belet, Ching-Tu and Shangri-La turns permanently away from Saturn on Titan's anti-Saturn side.

Titan's eight named dark albedo features group geographically into four assemblages according to center latitude and far or near side occupancy. Mezzoramia establishes its own single-member classification as the only south polar region-centered, Saturn-facing low albedo feature. Aaru and Fensal separate from their respective neighbors of Senkyo and Aztlan to group as Titan's northern equatorial belt-centered, Saturn-facing dark albedo features. Aztlan and Senkyo disassociate with Fensal and Aaru, respectively, to associate as southern equatorial belt-centered, Saturn-facing low albedo features. Belet, Ching-Tu and Shangri-La unite as Titan's southern equatorial belt-centered, anti-Saturn facing dark albedo features.

Detail of Titan With ISS (Imaging Science Subsystem) Backgroun Map shows equatorial belt dominance of dark albedo features (left to right: Belet, Ching-Tu, Shangri-La, Fensal and Aztlan) and remote southerly isolation of dark albedo feature Mezzoramia (lower right); map credit NASA/JPL/Space Science Institute: No known copyright restrictions, via IAU-USGS Astrogeology Science Center's Gazetteer of Planetary Nomenclature

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Detail of Titan VIMS (Visual and Infrared Mapping Spectrometer) Map shows dark albedo features of Fensal-Aztlan and Aaru-Senkyo as occupants of opposite sides of prime meridian on Titan's Saturn-facing side; map credit NASA/JPL/University of Arizona: No known copyright restrictions, via IAU-USGS Astrogeology Science Center's Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/titan_VIMS_comp.pdf

Detail of Titan With ISS (Imaging Science Subsystem) Backgroun Map shows equatorial belt dominance of dark albedo features (left to right: Belet, Ching-Tu, Shangri-La, Fensal and Aztlan) and remote southerly isolation of dark albedo feature Mezzoramia (lower right); map credit NASA/JPL/Space Science Institute: No known copyright restrictions, via IAU-USGS Astrogeology Science Center's Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/Titan_comp_ISSimage.pdf

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