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. Inkpen is a Faculty Fellow at NYU Gallatin. She is the author of "The Scientific Life in the Alpine: Recreation and Moral Life in the Field," (Isis, Sept 2018).

Amy Shira Teitel talks about Apollo and the community of people who are deeply attached to space history. Teitel is a spaceflight historian and the creator of the YouTube Channel, Vintage Space. She is also the author of two books, Breaking the Chains of Gravity: The Story of Spaceflight Before NASA and Apollo Pilot: The Memory of Astronaut Don Eisele.

Russell Potter discusses new developments in the search for answers about the tragic Franklin Expedition that disappeared in the Arctic in 1845. Potter is a professor of English and Media Studies at Rhode Island College. He's the author of Finding Franklin: The Untold Story of a 165-year Search.

Jake Robins and Michael Robinson talk about the quest to explore Mars: how it compares to earlier eras of exploration in the West and in the Arctic as well as its power to capture the imagination of thousands of people. Robins is the host of WeMartians, a podcast that considers the exploration of the Red Planet from a variety of angles, both technical and scientific.

Scott Wallace talks about his trip to Brazil reporting on the efforts of the Guajajara people to protect uncontacted tribes from loggers, miners, and poachers. Wallace is a professor of journalism at the University of Connecticut, a contributor to National Geographic, and a former reporter for CBS and CNN. He's the author of The Unconquered: In Search of the Amazon's Last Uncontacted Tribes.

Valerie Olson talks about why the idea of outer space as a "frontier" is giving way to one that frames it as a cosmic ecosystem. Olson is an associate professor of anthropology at University of California, Irvine. She is the author of Into the Extreme: U.S. Environmental Systems and Politics Beyond Earth.

In Part II, Ruth Gruenthal continues her story of her family's escape from France in 1940. She also discusses the challenges of living in the United States after the war.

Joyce Ashuntantang talks about her experiences as a traveler and a poet, from her childhood Cameroon to her years studying in Great Britain and the United States. Ashuntantang is a professor of English at Hillyer College, University of Hartford. She is the author of many works of poetry, including Beautiful Fire, published this year with Spears Media Press.

Ruth Gruenthal talks about her life in Germany as the Nazi Party came to power in the 1930s. Gruenthal and her family – along with thousands of Jewish refugees -- raced to escape France when the Germans invaded in the summer of 1940. Gruenthal is a practicing psychotherapist in New York City. She's also the daughter of the publisher Kurt Enoch who co-founded the New American Library in the United States after World War II.

Anthropologist P.J. Capelotti discusses the role of exploration archaeology in understanding the Pacific voyage of Kon-Tiki, the Arctic airship expeditions of Walter Wellman, and the fate of Orca II, a fishing boat used in the film Jaws.