Galileo Magnetometer Measurements: A Stronger Case for a Subsurface Ocean at Europa (original) (raw)
NASA/ADS
;
- Khurana, Krishan K. ;
- Russell, Christopher T. ;
- Volwerk, Martin ;
- Walker, Raymond J. ;
- Zimmer, Christophe
Abstract
On 3 January 2000, the Galileo spacecraft passed close to Europa when it was located far south of Jupiter's magnetic equator in a region where the radial component of the magnetospheric magnetic field points inward toward Jupiter. This pass with a previously unexamined orientation of the external forcing field distinguished between an induced and a permanent magnetic dipole moment model of Europa's internal field. The Galileo magnetometer measured changes in the magnetic field predicted if a current-carrying outer shell, such as a planet-scale liquid ocean, is present beneath the icy surface. The evidence that Europa's field varies temporally strengthens the argument that a liquid ocean exists beneath the present-day surface.
Publication:
Science
Pub Date:
August 2000
DOI:
Bibcode:
Keywords:
- PLANET SCI