Cassini radar views the surface of Titan

Science

Volumn 308, Issue 5724, 2005, Pages 970-974

  Elachi, C ^a   Wall, S ^a   Allison, M ^b   Anderson, Y ^a   Boehmer, R ^a   Callahan, P ^a   Encrenaz, P ^c   Flamini, E ^d   Franceschetti, G ^e   Gim, Y ^a   Hamilton, G ^a   Hensley, S ^a   Janssen, M ^a   Johnson, W ^a   Kelleher, K ^a   Kirk, R ^f   Lopes, R ^a   Lorenz, R ^g   Lunine, J ^g   Muhleman, D ^h   Ostro, S ^a   Paganelli, F ^a   Picardi, G ⁱ   Posa, F ^j   Roth, L ^a   Seu, R ⁱ   Shaffer, S ^a   Soderblom, L ^f   Stiles, B ^a   Stofan, E ^k   Vetrella, S ^e   West, R ^a   Wood, C ^l   Wye, L ^m   Zebker, H ^m   more..

^a CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

^b NASA GODDARD INSTITUTE FOR SPACE STUDIES   (United States)

^c OBSERVATOIRE DE PARIS   (France)

^d ITALIAN SPACE AGENCY   (Italy)

^e Facolta di Ingegneria   (Italy)

^f U S GEOLOGICAL SURVEY   (United States)

^g UNIVERSITY OF ARIZONA   (United States)

^h CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

ⁱ SAPIENZA UNIVERSITY OF ROME   (Italy)

^j POLITECNICO DI BARI   (Italy)

^k Proxemy Research Inc   (United States)

^l PLANETARY SCIENCE INSTITUTE   (United States)

^m STANFORD UNIVERSITY   (United States)

more..

Author keywords

[No Author keywords available]

Indexed keywords

GEOLOGY; HYDROCARBONS; ICE; IMAGE ANALYSIS; MAPPING; OPTICAL RESOLVING POWER; POROUS MATERIALS; SPACE APPLICATIONS; THERMAL EFFECTS; VOLCANOES;

CASSINI TITAN RADAR MAPPER; COMPLEX SURFACES; RESOLUTION MODES; TITAN'S SUFACE;

PLANETARY SURFACE ANALYSIS;

HYDROCARBON;

TITAN;

ARTICLE; ASTRONOMY; GEOLOGY; IMAGE ANALYSIS; IMAGE DISPLAY; MOON; PRIORITY JOURNAL; SPACE FLIGHT; SURFACE PROPERTY; TELECOMMUNICATION; TEMPERATURE; VOLCANO;

ATMOSPHERE; EXTRATERRESTRIAL ENVIRONMENT; HYDROCARBONS; ICE; ORGANIC CHEMICALS; RADAR; SATURN; SPACECRAFT; TEMPERATURE; VOLCANIC ERUPTION;

EID: 20844449234     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1109919     Document Type: Article

References (36)

1. B. Campbell, Radar Remote Sensing of Planetary Surfaces (Cambridge Univ. Press, Cambridge, 2002).
2. J. McCauley et al., Science 218, 1004 (1982).
3. R. Saunders et al., J. Geophys. Res. 97, 13067 (1992).
4. Instrument detail, observation geometries and details, resurfacing rate, radarclinometry methods, a coverage diagram, and related references are available as supporting material on Science Online.
5. The Huygens probe descended on 14 January 2005, reaching the surface at about 10.5°S, 192°W. See (30).
6. Titan geographical coordinates are per the IAU (37): In general terms, the equator is roughly Titan's orbital plane, and zero longitude is the subsatum point, with a libration of ±3° due to orbital eccentricity.
7. R. T. Pappalardo et al., in Jupiter: The Planet, Satellites, and Magnetosphere, F. Bagenal Ed. (Cambridge Univ. Press, Cambridge, 2004), pp. 363-396.
8. J. G. Patel et al., J. Geophys. Res. 104, 24,057 (1999).
9. C. C. Porco et al., Nature 434, 159 (2005).
10. B. J. Butler, M. Gurwell, Bull. Am. Astron. Soc. 36, 1075 (2004).
11. A. Grossman, D. Muhleman, Bull. Am. Astron. Soc. 24, 954 (1992).
12. This apparent asymmetry could result from the actual backscatter behavior departing from the assumed 1/sin(i) form at small incidence angles and/or from the finite resolution of the images. Even allowing for these effects, the relief is likely not much more than 100 m, and slopes do not approach the incidence angle, so that the features are not severely distorted by layover.
13. D. G. Jankowski, S. W. Squyres, Science 244, 1322 (1988).
14. J. Lunine, N. A. Artemieva, R. D. Lorenz, E. Flamini, paper presented at the 36th Annual Lunar and Planetary Science Conference, League City, TK 14-18 March 2005, abstract 1504.
15. S. Engel, J. I. Lunine, W. K. Hartmann, Planet. Space Sci. 43, 1059 (1995).
16. R. Lorenz, Planet. Space Sci. 45, 1009 (1997).
17. R. Lorenz, Planet. Space Sci. 44, 1021 (1996).
18. Campbell et al. (32) conducted observations with the Arecibo and Goldstone radio telescopes in November and December 2001 and late in 2002, obtaining disk-integrated echo spectra at longitudes 23° apart at 26°S.
19. S. Ostro, Rev. Mod. Phys. 65, 1235 (1993).
20. K. Peters, Phys. Rev. B 46, 801 (1992).
21. G. Black, D. Campbell, P. Nicholson, Icarus 151, 167 (2001).
22. S. Ostro et al., J. Geophys. Res. 97, 18227 (1992).
23. G. J. Black, D. B. Campbell, L. M. Carter, S. J. Ostro, Science 304, 553 (2004).
24. J. Harmon, D. Campbell, S. Ostro, M. Nolan, Planet. Space Sci. 47, 1409 (1999).
25. D. Muhleman, A. Grossman, B. Butler, Annu. Rev. Earth Planet. Sci. 23, 337 (1995).
26. We refer to the complex mix of nitrites and liquid and solid hydrocarbons produced by Titan's atmospheric photochemistry as "sludge." Dielectric constants vary, increasing with increasing mass density, from about 1.6 for methane to 3 or more for higher molecular weight materials, but 2.0 to 2.4 is a representative range for the mix. See (33).
27. R. Thompson, Icarus 86, 336 (1990).
28. Models for liquid compositions on Titan's surface are discussed in (34).
29. The density of polyacetylene is discussed in (35).
30. M. Tomasko et al., Nature, in press.
31. P. K. Seidelmann et al., Celest. Mech. Dynam. Astron. 82, 83 (2002).
32. D. B. Campbell, G. J. Black, L. M. Carter, S. J. Ostro, Science 302, 431 (2003).
33. R. Lorenz et al., Planet. Space Sci. 51, 353 (2003).
34. J. Lunine, Rev. Geophys. 31, 133 (1993).
35. D. Bott. in Handbook of Conducting Polymers, T. Skotheim, Ed. (Dekker, New York, 1986), pp. 1191-1232.
36. We gratefully acknowledge the many years of work by many hundreds of people in the development and design of the Cassini mission that have culminated in the results presented herein. The Cassini Project is a joint endeavor of NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI). Cassini is managed by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA.