BBC 地平线 洞穴隐秘生物

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.