The sand seas of Titan: Cassini RADAR observations of longitudinal dunes

被引:293
作者
Lorenz, RD [1 ]
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, GG
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
机构
[1] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA
[2] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[3] US Geol Survey, Flagstaff, AZ 86001 USA
[4] Proxemy Res, Bowie, MD 20715 USA
[5] Planetary Sci Inst, Tucson, AZ 85719 USA
[6] Wheeling Jesuit Coll, Wheeling, WV 26003 USA
[7] Stanford Univ, Stanford, CA 94305 USA
[8] NASA, Goddard Inst Space Studies, New York, NY 10025 USA
[9] Observ Paris, F-92195 Meudon, France
[10] Univ G DAnnunzio, Int Res Sch Planetary Sci, I-65127 Pescara, Italy
[11] Fac Ingn, I-80125 Naples, Italy
[12] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
[13] Univ Roma La Sapienza, I-00184 Rome, Italy
[14] Politecn Bari, Dipartimento Interateneo Fis, I-70126 Bari, Italy
[15] INFM, I-70126 Bari, Italy
[16] Agenzia Spaziale Italiana, I-00131 Rome, Italy
关键词
D O I
10.1126/science.1123257
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
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 similar to 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 similar to 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.
引用
收藏
页码:724 / 727
页数:4
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