太空边缘的微生物之谜

Some organisms commonly found on Earth’s surface lead a secret double life riding high in the atmosphere By Douglas Fox Seen from a scientific balloon 30 kilometers above New Mexico, the stratosphere is a gray zone between Earth and space. The air pressure at this height is one percent that at sea level and the ultraviolet radiation is intense. But scientists are learning that some microbes survive here, at least temporarily. The stratosphere is both beautiful and hostile — a purgatory between Earth and space, between life and death. Hover 30 kilometers above the ground, and you are nearly twice as high as any raincloud on Earth. The surface of the planet curves beneath you. …