The ionosphere of Europa from Galileo radio occultations

Science

Volumn 277, Issue 5324, 1997, Pages 355-358

  Kliore, A J ^a   Hinson, D P ^b   Flasar, F M ^c   Nagy, A F ^d   Cravens, T E ^e  

^a CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

^b STANFORD UNIVERSITY   (United States)

^c NASA GODDARD SPACE FLIGHT CENTER   (United States)

^d UNIVERSITY OF MICHIGAN   (United States)

^e UNIVERSITY OF KANSAS   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

OXYGEN; TRITIUM OXIDE; WATER;

ARTICLE; ASTRONOMY; ATMOSPHERE; PRIORITY JOURNAL; SPACE FLIGHT; THERMODYNAMICS;

FLIGHT EXPERIMENT; GALILEO PROJECT; LONG DURATION; UNMANNED;

ATMOSPHERE; EXTRATERRESTRIAL ENVIRONMENT; HYDROGEN; JUPITER; MAGNETICS; OXYGEN; TEMPERATURE; WATER;

EID: 0030848772     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.277.5324.355     Document Type: Article

References (19)

1. Radio occultations, in which a spacecraft appears to go behind a planetary body as viewed from Earth, allow the spacecraft-Earth radio link to traverse the ionosphere and atmosphere of the occulting body. Interpretation of the effects on the phase and amplitude of the signal received on Earth of refraction and defocusing in the planetary atmosphere and ionosphere allows one to infer the electron density structure in the ionosphere and the temperature-pressure profiles and absorption characteristics of the neutral atmosphere. This technique has been used with much success to measure the characteristics of the ionospheres and atmospheres of Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, as well as Saturn's satellite Titan, Neptune's Triton, and Jupiter's Io and now Europa (12).
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19. We wish to acknowledge the contributions of the staff of the Galileo Project, who have carried out a highly successful mission under difficult circumstances; the Galileo Navigation team, with W. E. Kirhofer and J. Johannesen, without whose precise orbits this work would not have been possible; and the personnel of the Jet Propulsion Laboratory Multimission Radio Science team, especially S. Asmar, R. Herrera, D. Chong, P. Eshe, P. Priest, J. Caetta, T. Rebold, and S. Abbate, who planned and successfully executed the data acquisition process. Special thanks are due to J. Twicken and P. Schinder for their assistance in data analysis at Stanford and Goddard Space Flight Center, and to D. M. Hunten, W. H. Ip, and two anonymous referees for helpful suggestions and comments. This work was supported by NASA contracts and grants.