Horizon
Season 40 Episode 10 - The Secret Life Of Caves
Set against the back drop of awe inspiring geological beauty, a strange scientific adventure sets out to discover how a mineral clad cave network - the height of a 30 storey building and the length of six football fields - came to exist deep below the Guadalupe Mountains in North America. But this journey soon unravels a multitude of inexplicable phenomena and obscure geological formations, leading to the discovery of extreme rock-eating microbes - a testimony from primordial Earth and a glimpse of life elsewhere in the Solar System. Geologists believed that all limestone caves were formed by rain and underground water percolating through cracks in the rocks. Absorbing carbon dioxide from the soil, this water becomes weak carbonic acid, nibbling away at limestone, etching out networks of subterranean caves.
Episodes in Season 40
The Mystery Of Easter Island
60 min
Living Nightmare
60 min
Averting Armageddon
60 min
Dirty Bomb
60 min
Sexual Chemistry (Update)
60 min
The Day We Learned To Think
60 min
Trial and Error
60 min
Earthquake Storms
60 min
Life On Mars (Update)
60 min
The Secret Life Of Caves
60 min
God On The Brain
60 min
Flight 587
60 min
SARS: The True Story
60 min
The Big Chill
60 min
The Bible Code
60 min
Last Flight of the Columbia
60 min
The Hunt for an AIDS Vaccine
60 min
Percy Pilcher's Flying Machine
60 min
Time Trip
60 min
