Birgit Sattler (1969 - ) Notable Achievements Discovering that the atmosphere is a microbial ecosystem harboring active microbes; and Lake Paula, an undiscovered permanently ice-covered lake in Antarctica. Occupation/Field of Study: Ph.D. Microbiology and Limnology; Limnolodist (specialist in the study of fresh water ponds and lakes.) Period of Activity: 2001- current; Biography Brigit Sattler is an explorer in both the Arctic and the atmosphere.  She made the pioneering discovery that clouds are filled with living organisms.  Having completed her Ph.D. on microorganisms in mountain lakes, her interests include bacterial production and activity, ice physics, and microbial processes in snow and in the atmosphere.  Her current project, Origin and Dynamics of Bacteria in the Winter Cover of a High Mountain Lake, investigates the classification of bacteria that inhabit ice, as compared to those found in snow from the North and South Poles.