Professor Len Tyler

Fall 2000-2001

Date: Wednesday, October 25, 2000
Time: 4:15-5:30 PM; Refreshments at 4:00 PM
Location: 380-380Y

Using Radio Techniques to Assist in the Search for Life on Europa

Prof. Antony Fraser-Smith
Electrical Engineering, Stanford University


Recent measurements by the Galileo space probe near Europa, Jupiteršs fourth largest moon, strongly support earlier speculations that there is a liquid ocean beneath the thick and remarkably smooth layer of water ice that covers the entire surface of Europa. Partly for this reason, NASA is now giving highest priority in its planetary program to the exploration of Europa and the search for life in its ocean. Given the large distance between the Earth and Jupiter/Europa, and NASAšs emphasis on "faster, better, cheaper" projects, it will not be easy detecting life beneath the ice layer, whose thickness is unknown but which could well lie anywhere in the range 1 ­ 100 km. Under the circumstances, the use of space-probe based radio sounding techniques appear to have a lot to offer. They could provide a first indication of the ice thickness, and then they could perhaps help in the selection of a least-thick region for a penetrating life-detecting probe to be deployed. Naturally, there are some problems that need to be dealt with before these radio techniques can be used. Most importantly, we donšt know the electrical conductivity of Europašs ice, and a highly conducting ice layer will make radio sounding very difficult. So we will probably have to start by using radio techniques to determine the conductivity of the ice! These and other related radio issues will be explored in this seminar.