On January 23, 1960 Jacques Piccard and then USN Lt. Don Walsh dropped the bathyscaphe Trieste to the bottom of the Challenger Deep in the Mariana Trench some 35,797 feet down. It was a major milestone that has only been replicated once in the ensuing 56 years. Host Greg Martin spends a few minutes talking about that trip to the deepend known location in the ocean with Ret. Capt. Don Walsh.