Underwater explorer and photographer Jill Heinerth has dived into unmapped caves deep in the earth, and beneath a giant iceberg. She's seen hidden creatures old as dinosaurs, and witnessed scenes of surreal beauty. Her work is so dangerous, over a hundred of her friends and colleagues have died in caves. She talks about the risks and rewards of her work.
That's the claim of oceanographer Dr. Robert Ballard, who says we've explored less than 1% of the deep sea. Ballard has made dozens of dives in manned submersibles, and has been instrumental in the development of research based on robotic, tele-presence. He joins Fresh Air to share some of the discoveries he's made throughout his career.