Europa's Differentiated Internal Structure: Inferences from Four Galileo Encounters
J. D. Anderson,
G. Schubert,
R.
A. Jacobson,
E. L. Lau,
W. B. Moore,
W. L. Sjogren
Radio Doppler data from four encounters of the Galileo spacecraft
with the jovian moon Europa have been used to refine models of
Europa's interior. Europa is most likely differentiated into a
metallic core surrounded by a rock mantle and a water ice-liquid outer
shell, but the data cannot eliminate the possibility of a uniform
mixture of dense silicate and metal beneath the water ice-liquid shell.
The size of a metallic core is uncertain because of its unknown
composition, but it could be as large as about 50 percent of Europa's
radius. The thickness of Europa's outer shell of water ice-liquid must
lie in the range of about 80 to 170 kilometers.
J. D. Anderson, R. A. Jacobson, E. L. Lau, W. L. Sjogren, Jet Propulsion Laboratory, California Institute of
Technology, Pasadena, CA 91109, USA. G. Schubert and W. B. Moore, Department of Earth and Space Sciences, Institute of Geophysics
and Planetary Physics, University of California, Los Angeles, CA 90095, USA.
