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Surface Penetrating Radar Simulations for Jupiter's Icy MoonsThe 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.
Document ID
20040035669
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Markus, Thorsten
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Gogineni, S. P.
(Kansas Univ. Lawrence, KS, United States)
Green, J. L.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Reinisch, B. W.
(Massachusetts Univ. Lowell, MA, United States)
Song, P.
(Massachusetts Univ. Lowell, MA, United States)
Fung, S. F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Benson, R. F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Taylor, W. W. L.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Cooper, F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Lunar And Planetary Science And Exploration
Meeting Information
Meeting: AGU Meeting
Location: San Francisco, CA
Country: United States
Start Date: December 8, 2003
End Date: December 11, 2003
Sponsors: American Geophysical Union
Distribution Limits
Public
Copyright
Other

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