Dive into deep time to discover how fossils form, the ocean's surprising origins, and more. More

What do fossilized leaves, an asteroid, and Florida sinkholes have in common? Dr. Kirk Johnson is Sant Director at the Smithsonian Institution, National Museum of Natural History, and has the answers. Kirk oversees one of the largest natural history collections on the planet – and he’s spent his career digging into the story of life on Earth across millions (and billions) of years.

AIR DATE 8/18/25