Relatively speaking, very little of the world’s oceans have been explored. But cave diver and author Jill Heinerth, is doing all she can. Her new book, Into The Planet is her firsthand account of exploring the earth’s final frontier: the hidden depths of our oceans and the caves she finds down there. Heinerth is the first in history to dive deep into an Antarctic iceberg and led a team that discovered the ancient watery remains of Mayan civilizations. She has descended farther into the inner depths of our planet than any other woman & brings back some very cool stories.