Galilean Satellites Gravity Investigations and Interior Structure with Future Missions

Details Galilean Satellites Gravity Investigations and Interior Structure with Future Missions Galilean Satellites Gravity Investigations and Interior Structure with Future Missions

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agufm.p51e1172a&link_type=abstract

American Geophysical Union, Fall Meeting 2009, abstract #P51E-1172

Mathematics

Logic

[1221] Geodesy And Gravity / Lunar And Planetary Geodesy And Gravity, [5417] Planetary Sciences: Solid Surface Planets / Gravitational Fields, [6994] Radio Science / Instruments And Techniques

Scientific paper

Investigations of gravitational fields for interior structure modeling of the Galilean satellites will benefit from advances in Radio Science instrumentation technology. About two orders of magnitude improvement in measurement accuracy relative to the radio link-limited Galileo mission can be obtained from simultaneous coherent Ka- and X-bands. Advanced calibration and processing methods have also been developed to improve science data quality. The gravity instrumentation is centered on a transponder operating at Ka-band frequency (32-34 GHz) for precision Doppler (to ~3 micron/s two-way, over 1000 s integration times, after all calibrations) and improved ranging data. Parallel architectural concepts have been developed in the US and Europe for the Europa and Ganymede orbiters. The Galilean satellites represent two classes of internally active satellites which likely maintain liquid subsurface water oceans, either beneath a modest ice layer above and in contact with a rocky ocean sea-floor (Europa), or sandwiched between a relatively thick outer ice shell and high-pressure ice phases below (Ganymede and Callisto). Among the scientific objectives to be fulfilled by Radio Science tracking are: 1) Deep interior structure: the radial density distribution of the deep satellite interiors will be inferred by improved measurements of their moment of inertia factor and low-degree gravity field coefficients. The assumption of hydrostatic equilibrium will be tested by separate determination of the static components of the gravitational field coefficients J2 and C22. 2) Crust and lithosphere: the gravitational signature of intrinsic density anomalies and regional topographic features will be inferred from higher-degree gravity data (we aim at determining at least the degree 10 gravity field harmonics) in combination with laser altimetry, thereby imposing constraints on the geologic histories and thermal evolutions of the moons. 3) The detection of a global subsurface water ocean and the characterization of the ocean and the overlying ice shell require measuring the response of the ice shell to tidal forces exerted by Jupiter along the slightly eccentric orbit of each satellite using gravity measurements and Laser altimetry. The dynamical tidal Love number k2, characterizing the variation in the gravitational potential due to the satellite's time varying tidal distortion, is inferred from time-variable contributions to the low-degree coefficients J2 and C22 of the gravitational field. The Love number h2 characterizing the radial displacement will be determined by using a laser altimeter in addition to the gravity measurements.

Affiliated with

Also associated with

No associations

Rating

Galilean Satellites Gravity Investigations and Interior Structure with Future Missions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Galilean Satellites Gravity Investigations and Interior Structure with Future Missions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Galilean Satellites Gravity Investigations and Interior Structure with Future Missions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1773648