HR: 0830h
AN: P31B-1063    [PDF]
TI: Surface Penetrating Radar Simulations for Jupiter`s Icy Moons
AU: * Markus, T
EM: Thorsten.Markus@nasa.gov
AF: NASA/GSFC, Code 975, Greenbelt,, MD 220771 United States
AU: Gogineni, P
EM: gogineni@ittc.ku.edu
AF: ITTC, University of Kansas, Lawrence, Lawrence, KS 66045 United States
AU: Green, J L
EM: James.L.Green@nasa.gov
AF: NASA/GSFC, Code 630, Greenbelt, MD 20771 United States
AU: Reinisch, B W
EM: bodo_reinisch@uml.edu
AF: Ctr. f. Atmospheric Research, Univ. of Mass., Lowell, Lowell, MA 01854 United States
AU: Song, P
EM: paul_song@uml.edu
AF: Ctr. f. Atmospheric Research, Univ. of Mass., Lowell, Lowell, MA 01854 United States
AU: Fung, S
EM: fung@mail630.gsfc.nasa.gov
AF: NASA/GSFC, Code 630, Greenbelt, MD 20771 United States
AU: Benson, R F
EM: Robert.F.Benson@nasa.gov
AF: NASA/GSFC, Code 692, Greenbelt, MD 20771 United States
AU: Taylor, W L
EM: taylor@mail630.gsfc.nasa.gov
AF: NASA/GSFC, Code 630, Greenbelt, MD 20771 United States
AU: Cooper, J F
EM: jfcooper@pop600.gsfc.nasa.gov
AF: NASA/GSFC, Code 630, Greenbelt, MD 20771 United States
AU: Garcia, L
EM: garcia@mail630.gsfc.nasa.gov
AF: NASA/GSFC, Code 630, Greenbelt, MD 20771 United States
AU: Gallagher, D L
EM: Dennis.L.Gallagher@nasa.gov
AF: NASA NASA, Marshall Space Flight Center, Huntsville, AL 35812 United States
AB: The icy moons of Jupiter (Europa, Callisto, and Ganymede) are of similar overall composition but show different surface features as a result of different sub-surface processes. Furthermore, each of these moons could have a liquid ocean of water buried underneath the icy crust, but their depth can only be speculated. For Europa, estimates put the thickness of the ice shell anywhere between 2-30 km, with a few models predicting up to 100 km. Much of the uncertainties are due to the largely unknown temperature gradients and levels of water impurities across different surface layers. One of the most important geological processes is the possible transportation of heat by ice convection. If the ice is convecting, then an upper limit of about 20 km is set for the depth of the ocean underneath. Convection leads to a sharp increase in temperature followed by a thick region of nearly constant temperature. If ice is not convecting, then an exponentially increasing temperature profile is expected. The crust is thought to be a mixture of ice and rock, and although the exact percentage of rock is not known, it is expected to be low. Additionally, the ice crust could contain salt, similar to sea ice on Earth. The exact amount of salt and how that amount changes with depth is also unknown. In preparation for the Jupiter Icy Moons Orbiter (JIMO) mission, we performed simulations for a surface-penetrating radar investigating signatures for different possible surface and sub-surface structures of these moons in order to estimate the applicability of using radar with a frequency range between 1 and 50 MHz. This includes simulations of power requirements, attenuation losses, layer resolutions for scenarios with and without the presence of a liquid ocean underneath the ice, cases of convecting and non-convecting ice, different impurities within the ice, and different surface roughnesses.
DE: 6218 Jovian satellites
DE: 6297 Instruments and techniques
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting