Pulse of the Planet is a weekday radio show that "provides its listeners with a two-minute sound portrait of Planet Earth, tracking the rhythms of nature, culture and science worldwide and blending interviews and extraordinary natural sound."
 

Program #2582 January 2002 Caves: Mars Connection   Listen to this program in MP3 Listen to this program in streaming audio ambiance: breathing sound underwater, tank One key to understanding life on Mars could be found deep below the surface of our own planet, in the dark waters of ancient saltwater caves. I’m Jim Metzner, and this is the Pulse of the Planet. In the absence of sunlight bacteria in these caves have developed a special ability to derive energy from hydrogen sulfide, and other chemicals in the water. Tom Iliffe is a veteran cave diver, and a professor of marine biology at Texas A&M University. In the background we are listening to the sounds of divers in saltwater caves. “Unlike surface ecosystems where organisms feed off of plants or other animals that feed on plants, there are no plants in the underwater caves because there’s no light. Instead of using light as a primary energy source, we have bacteria that may use chemical reactions as a source of energy.” Because these bacteria evolved under such harsh conditions, Dr. Iliffe believes they could resemble the kind of organisms which might survive on Mars. “Life in caves is essentially life in extreme environments. We’re talking about environments where there’s no light, very limited food resources, considerable isolation of the habitat. These may be conditions that are similar to conditions present on other planets in our solar system. Recently there’s been discoveries of possibilities of water on Mars, and water in the form of springs coming up and seeping out of the rock. If there is life on Mars, perhaps it’s life down in underwater caves on Mars, similar to the underwater caves that we’re diving in here on planet Earth.” First broadcast on 22-JAN-02

Other Pulse of the Planet episodes:

Cave Diving Living Fossils Ancient Life