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Radebaugh J, Ventra D, Lorenz RD, Farr T, Kirk R, Hayes A, Malaska MJ, Birch S, Liu ZYC, Lunine J, Barnes J, Le Gall A, Lopes R, Stofan E, Wall S, Paillou P. Alluvial and fluvial fans on Saturn's moon Titan reveal processes, materials and regional geology. ACTA ACUST UNITED AC 2016. [DOI: 10.1144/sp440.6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractFans, landforms that record the storage and transport of sediment from uplands to depositional basins, are found on Saturn's moon Titan, a body of significantly different process rates and material compositions from Earth. Images obtained by the Cassini spacecraft's synthetic aperture radar reveal morphologies, roughness, textural patterns and other properties consistent with fan analogues on Earth also viewed by synthetic aperture radar. The observed fan characteristics on Titan reveal some regions of high relative relief and others with gentle slopes over hundreds of kilometres, exposing topographic variations and influences on fan formation. There is evidence for a range of particle sizes across proximal to distal fan regions, from c. 2 cm or more to fine-grained, which can provide details on sedimentary processes. Some features are best described as alluvial fans, which implies their proximity to high-relief source areas, while others are more likely to be fluvial fans, drawing from larger catchment areas and frequently characterized by more prolonged runoff events. The presence of fans corroborates the vast liquid storage capacity of the atmosphere and the resultant episodic behaviour. Fans join the growing list of landforms on Titan derived from atmospheric and fluvial processes similar to those on Earth, strengthening comparisons between these two planetary bodies.
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Affiliation(s)
- Jani Radebaugh
- Brigham Young University, S-389 ESC, Provo, UT 84601, USA
| | | | - Ralph D. Lorenz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - Tom Farr
- NASA Jet Propulsion Laboratory, Pasadena, CA 91109, USA
| | - Randy Kirk
- US Geological Survey, Astrogeology Division, Flagstaff AZ 86001, USA
| | - Alex Hayes
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | | | - Sam Birch
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - Zac Yung-Chun Liu
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - Jonathan Lunine
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - Jason Barnes
- Department of Physics, University of Idaho, Moscow, ID 83844, USA
| | - Alice Le Gall
- LATMOS Observatoire de Versailles Saint-Quentin-en-Yvelines (OVSQ), Paris, France
| | - Rosaly Lopes
- NASA Jet Propulsion Laboratory, Pasadena, CA 91109, USA
| | | | - Steve Wall
- NASA Jet Propulsion Laboratory, Pasadena, CA 91109, USA
| | - Philippe Paillou
- Observatoire Aquitain des Sciences de l'Univers, Universite de Bordeaux, Floirac, France
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Possible tropical lakes on Titan from observations of dark terrain. Nature 2012; 486:237-9. [PMID: 22699614 DOI: 10.1038/nature11165] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 04/26/2012] [Indexed: 11/08/2022]
Abstract
Titan has clouds, rain and lakes--like Earth--but composed of methane rather than water. Unlike Earth, most of the condensable methane (the equivalent of 5 m depth globally averaged) lies in the atmosphere. Liquid detected on the surface (about 2 m deep) has been found by radar images only poleward of 50° latitude, while dune fields pervade the tropics. General circulation models explain this dichotomy, predicting that methane efficiently migrates to the poles from these lower latitudes. Here we report an analysis of near-infrared spectral images of the region between 20° N and 20° S latitude. The data reveal that the lowest fluxes in seven wavelength bands that probe Titan's surface occur in an oval region of about 60 × 40 km(2), which has been observed repeatedly since 2004. Radiative transfer analyses demonstrate that the resulting spectrum is consistent with a black surface, indicative of liquid methane on the surface. Enduring low-latitude lakes are best explained as supplied by subterranean sources (within the last 10,000 years), which may be responsible for Titan's methane, the continual photochemical depletion of which furnishes Titan's organic chemistry.
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Mueller-Wodarg I, Yelle R. Progress in understsanding Titan's atmosphere and space environment. Preface. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:603-605. [PMID: 19008188 DOI: 10.1098/rsta.2008.0251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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