The Foundation established the Deep Carbon Observatory (DCO) in 2009 to achieve major advances in understanding of carbon, the element of life, in geologically diverse deep continental and marine environments. The Observatory's plan includes a component whose objective is to describe the types of life that occur, their adaptive and evolutionary strategies, and the limits-and possibly origins-of life. In fact, evidence exists for life in all deep environments where there is liquid water. The environments include oil wells, deep granitic and basaltic aquifers, sandstone cores, clays, gold seams, and deep marine sediments. With Foundation support, an international network of microbiologists and geneticists headquartered at Oregon State University will begin a comprehensive survey of the diversity, distribution, and abundance of life in representative deep environments. Earth's microbes probably amount to 90% or more of all life. The total number of cells might be a nonillion, one thousand times one billion times one billion times one billion, or 10 to the 30th power, and the subsurface biomass may be 90% of all microbial cells. For many environments, however, there are no or sparse data, and the diversity is just now being explored thanks to new gene sequencing technologies. A key technology is "pyrotag" sequencing, which allows low-cost processing of massive amounts of DNA. The method has been applied to very few samples from deep environments. As a base, this project would examine well-preserved samples from four deep settings chosen for their variety and extensive contextual information, for example, permafrost more than 600 meters below the surface on continents. A community meeting in the second year of the project will help build the global network of experts in deep life to achieve the eventual DCO goals.