Detection of a Europan Ocean from Tides and Rotation

Details Detection of a Europan Ocean from Tides and Rotation Detection of a Europan Ocean from Tides and Rotation

May 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000dda....31.0408y&link_type=abstract

American Astronomical Society, DDA Meeting #31, #04.08; Bulletin of the American Astronomical Society, Vol. 32, p.860

Astronomy and Astrophysics

Astronomy

Scientific paper

Europa's icy surface displays tectonic evidence of thin shell (<20km) dynamics while the predicted total depth of the ice-water layer is 80-140km from moment of inertia. Jupiter raises 20-30m periodic tide resulting from orbit eccentricity. This 3.55d tide can be detected from an orbiting spacecraft using altimetry (which measures Love number h2 and Doppler tracking (which observes the gravimetric k2 Love number). Measurement of both Love numbers first establishes the existence/absence of a global water ocean and second determines the relative deformation of ice shell and mantle. Shell tidal amplitude constrains the product of the mean shell depth d4R times rigidity μ 4. Solid ice μ 4=4 x 1010 dyne-cm might be reduced by fractures and partial melt. Jupiter also drives an axial oscillation of Europa's figure which is proportional to esin M where M is the orbital mean anomaly. This rotation amplitude is sensitive to whether the ice shell is grounded or floats free. The predicted solid body rotation amplitude is 140m at the equator while the predicted amplitude for a 'deep ocean' (> 10km) is <85m. The most interesting feature of decoupled motion is that shell libration amplitude is dependent on shell rigidity and less so on thickness. Thus, precise measurement of this amplitude along with the above tidal signatures determines both shell thickness and rigidity. This abstract presents the results of one phase of research carried out at the Jet Propulsion Laboratory, CalTech under contract with NASA.

Affiliated with

Also associated with

No associations

Rating

Detection of a Europan Ocean from Tides and Rotation 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 Detection of a Europan Ocean from Tides and Rotation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of a Europan Ocean from Tides and Rotation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1128687