Neil deGrasse Tyson features his interview with master navigator and traditional Polynesian voyager Nainoa Thompson and discusses the science of celestial navigation with comedian Maeve Higgins and navigation instructor Frank Reed. Author Dava Sobel discusses the "longitude problem" from her best-selling book, Longitude.

Neil deGrasse Tyson features his interview with former astronaut Mae Jemison and discusses the challenges of interstellar travel with comedian Godfrey and theoretical physicist Lawrence Krauss. Biomedical engineer Ronke Olabisi contributes.