Belet Is Equatorial Dark Albedo Feature on Titan's Anti-Saturn Side

Summary: Belet is an equatorial dark albedo feature on Titan's anti-Saturn side that is recognized as the largest of Titan's three largest sand seas.

Topographic maps show Belet's dark dunes, with heights of 100 to 150 meters (300 to 500 feet), and lighter, elevated, dune-less areas; maps in equirectangular projection, with north at top, created from images obtained during Cassini spacecraft's T8 flyby of Oct. 28, 2005, and T21 flyby of Dec. 12, 2006; black-and-white image (above) is color-coded (below) for elevations; map region, which covers about 450 kilometers (280 miles), is centered near 9 degrees south latitude, 290 degrees west longitude; image addition date 2009-03-24; image credit NASA/JPL-Caltech/ASI/USGS: May be used for any purpose without prior permission, via NASA JPL Photojournal

Belet is an equatorial dark albedo feature on Titan's anti-Saturn side that numbers as the largest of the Saturnian moon's three largest sand seas.

Belet is centered at minus 5 degrees south latitude, 255 degrees west longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The Gazetteer places the low albedo feature's northernmost and southernmost latitudes at its center latitude of minus 5 degrees south and its easternmost and westernmost longitudes as its center longitude of 255 degrees west longitude.

Belet lies to the west of Adiri, the anti-Saturn side's bright equatorial albedo feature. Adiri is centered at minus 10 degrees south latitude, 210 degrees west longitude. Adiri's center coordinates are given as the high albedo feature's northernmost-southernmost latitudes and easternmost-westernmost longitudes.

Belet lies to the east of the Saturn-facing side's far western dark albedo features, Aaru and Senkyo. Northern equatorial-centered Aaru is positioned above southern equatorial-centered Senkyo in Titan's equatorial belt.

Aaru is centered at 10 degrees north latitude, 340 degrees west longitude. Its northernmost-southernmost latitudes and easternmost-westernmost longitudes coincide with its center coordinates.

Senkyo is centered at minus 5 degrees south latitude, 320 degrees west longitude. Its center latitude and longitude are identified as the low albedo feature's northernmost-southernmost latitudes and easternmost-westernmost longitudes, respectively.

Belet heads Shangri-La and Fensal as the largest of Titan's three largest sand seas, according to planetary geophysicist Antoine Lucas and seven co-authors in their study, "Texture and Composition of Titan's Equatorial Sand Seas Inferred From Cassini SAR Data," published in the October 2019 issue of Journal of Geophysical Research JGR: Planets. Dark albedo feature Shangri-La has center coordinates of minus 10 degrees south latitude, 165 degrees west longitude. the anti-Saturn side resident's center latitude and longitude are recorded as its northernmost-southernmost latitudes and easternmost-westernmost longitudes, respectively. Dark albedo feature Fensal is centered at 5 degrees north latitude, 30 degrees west longitude. The Saturn-facing side occupant's center coordinates are given as its northernmost-southernmost latitudes and easternmost-westernmost longitudes.

Belet's extensive sand sea sprawls across Titan's trailing hemisphere. Titan's largest dune field stretches latitudinally from 25 degrees north to minus 30 degrees south and longitudinally from 65 degrees west to 150 degrees west, according to planetary geologist Bradley Bishop and three co-authors in "Dune Width and Spacing in Titan's Belet Sand Sea in Relation to Topography Highlights Potential Sediment Transport Patterns," their presentation at the 47th Lunar and Planetary Science Conference, held March 21-25, 2016, at The Woodlands Waterway Marriott Hotel and Convention Center in The Woodlands, Texas.

Altitude and latitude influence the sizes and patterns of dunes, according to NASA Jet Propulsion Laboratory's (JPL) Photojournal post, "Dune Patterns," published Jan. 23, 2012. Images of dark albedo features Belet and Fensal obtained by the Cassini spacecraft's radar instrument on Oct. 28, 2005, and April 10, 2007, reveal the wide dunes, with thicker blanketed interdunes, associated with Belet's low altitude and longitude. Thin, widely separated dunes with thinly covered interdunes characterize Fensal's higher elevation and latitude. In a comparison with Earth's deserts, Belet's dunes resemble the abundant sediment available in the Oman dunes of Oman, Saudi Arabia, United Arab Emirates and Yemen. Known as Rub' al Khali (Arabic: "Empty Quarter"), the Oman dunes occur as a southern extension of the Arabian Peninsula's vast Arabian Desert. Contrastingly, Fensal's dunes are reminiscent of the limited sediment found in the Kalahari (Tswana: Kgala, "the great thirst,",or Kgalagadi, "a waterless place") sand dunes of Botswana, Namibia and South Africa in Southern Africa.

The International Astronomical Union approved Belet's name in 2006. The Gazetteer of Planetary Nomenclature traces the dark equatorial albedo feature's name to the "Malay afterworld reached by a flower-lined bridge." The IAU convention for Titan's albedo features draws names of "Sacred or enchanted places, paradise, or celestial realms from legends, myths, stories, and poems of cultures from around the world," according to the Gazetteer's page on “Categories (Themes) for Naming Features on Planets and Satellites."

image of dark albedo feature Belet acquired Jan. 15, 2010, by Cassini spacecraft's Narrow-Angle Camera (NAC), with 938 nanometer near-infrared light wavelength-centered spectral filter; trailing hemisphere image obtained at an approximately distance of 1.2 million kilometers (746,000 miles) from Titan and at Sun-Titan-spacecraft, or phase, angle of 51 degrees; image addition date 2010-04-20; image credit NASA/JPL/Space Science Institute: May be used for any purpose without prior permission, via NASA JPL Photojournal

Acknowledgment

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

Image credits:

Topographic maps show Belet's dark dunes, with heights of 100 to 150 meters (300 to 500 feet), and lighter, elevated, dune-less areas; maps in equirectangular projection, with north at top, created from images obtained during Cassini spacecraft's T8 flyby of Oct. 28, 2005, and T21 flyby of Dec. 12, 2006; black-and-white image (above) is color-coded (below) for elevations; map region, which covers about 450 kilometers (280 miles), is centered near 9 degrees south latitude, 290 degrees west longitude; image addition date 2009-03-24; image credit NASA/JPL-Caltech/ASI/USGS: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA11829

image of dark albedo feature Belet acquired Jan. 15, 2010, by Cassini spacecraft's Narrow-Angle Camera (NAC), with 938 nanometer near-infrared light wavelength-centered spectral filter; trailing hemisphere image obtained at an approximately distance of 1.2 million kilometers (746,000 miles) from Titan and at Sun-Titan-spacecraft, or phase, angle of 51 degrees; image addition date 2010-04-20; image credit NASA/JPL/Space Science Institute: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA12615

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