Publikationsdatum:
2006-05-06
Beschreibung:
The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show approximately 100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills. The distribution and orientation of the dunes support a model of fluctuating surface winds of approximately 0.5 meter per second resulting from the combination of an eastward flow with a variable tidal wind. The existence of dunes also requires geological processes that create sand-sized (100- to 300-micrometer) particulates and a lack of persistent equatorial surface liquids to act as sand traps.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lorenz, R D -- Wall, S -- Radebaugh, J -- Boubin, G -- Reffet, E -- Janssen, M -- Stofan, E -- Lopes, R -- Kirk, R -- Elachi, C -- Lunine, J -- Mitchell, K -- Paganelli, F -- Soderblom, L -- Wood, C -- Wye, L -- Zebker, H -- Anderson, Y -- Ostro, S -- Allison, M -- Boehmer, R -- Callahan, P -- Encrenaz, P -- Ori, G G -- Francescetti, G -- Gim, Y -- Hamilton, G -- Hensley, S -- Johnson, W -- Kelleher, K -- Muhleman, D -- Picardi, G -- Posa, F -- Roth, L -- Seu, R -- Shaffer, S -- Stiles, B -- Vetrella, S -- Flamini, E -- West, R -- New York, N.Y. -- Science. 2006 May 5;312(5774):724-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA. rlorenz@lpl.arizona.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16675695" target="_blank"〉PubMed〈/a〉
Schlagwort(e):
*Extraterrestrial Environment
;
Geologic Sediments
;
Hydrocarbons/chemistry
;
Methane/chemistry
;
Particle Size
;
Radar
;
*Saturn
;
Spacecraft
;
Wind
Print ISSN:
0036-8075
Digitale ISSN:
1095-9203
Thema:
Biologie
,
Chemie und Pharmazie
,
Informatik
,
Medizin
,
Allgemeine Naturwissenschaft
,
Physik
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