Traveling this holiday? Be sure this recommendation is on your list. Seriously. Your drive or flight time will fly by listening to Radiolab's The Dark Side of the Earth. Astronaut Dave Wolf, has been to space 4 times, completed 7 spacewalks and logged over 4,000 hours up there. When asked to tell a story about darkness, he describes the extremes of light and dark in space, relives a heart-pounding close call, and shares one of the most tranquil moments of his life. Out in the blackness of space, the contrast between light and dark is unimaginably extreme – every 45 minutes, you plunge between absolute darkness on the night-side of Earth and blazing light as the sun screams into view. These terrifyingly beautiful images are crystal clear, thanks to Wolf's stories. Our minds and ears were consistently filled with excitement and wonder up until the very last second.