Jorge Canizares-Esguerra discusses the 16th century mining center of Potosí and how its peoples and technologies shaped 16th century science.

Dani Inkpen talks about expedition life in the Juneau Icefield, home to some of the most spectacular glaciers in North America. In the 1940s, it was the place where science and mountaineering joined hands and, occasionally, came into conflict.

Cannibals, headless men, and giants were common figures of Medieval and Renaissance maps. Historian Surekha Davies tells us why we need to take these figures seriously. Davies is the author of Renaissance Ethnography and the Invention of the Human: New Worlds, Maps and Monsters.

Russell Potter discusses new developments in the search for answers about the tragic Franklin Expedition that disappeared in the Arctic in 1845.

In 1946, Swedish and Finnish observers reported "ghost rockets" flying over Scandinavia. In the United States, they became known as "flying saucers." Historian Greg Eghigian discusses the science and culture of UFOs in the twentieth century (rebroadcast).