Webexploring the deep tracks the paths of six objects associated with the challenger expedition, including the baillie sounding machine, a starfish, a photographic. Webnpr's a martinez speaks with scuba diver and writer susan casey about her new book, the underworld: Journeys to the depths of the ocean. Webpublished to mark the 150th anniversary of the launch of the challenger expedition, the challenger expedition: Exploring the ocean's depths tells the story of the. Webexploring the deep tracks the paths of six objects associated with the challenger expedition, including the baillie sounding machine, a starfish, a photographic.
