Pope, K. O. (Geo Eco Arc Research La Canada, CA, United States)
Ocampo, A. C. (Jet Propulsion Lab. California Inst. of Tech., Pasadena., United States)
Baines, K. H. (Jet Propulsion Lab. California Inst. of Tech., Pasadena., United States)
Ivanov, B. A. (Academy of Sciences USSR, Moscow., United States)