In December 2008 the Trustees encouraged development of a new basic science program on "Deep Carbon," tentatively described in the Transition Strategy paper provided to the Trustees. With Trustee support, the Carnegie Institution of Washington (CIW) will launch the development of a worldwide Deep Carbon Observatory and serve as its anchor institution. The Deep Carbon Program would address four major areas. First, it would seek to estimate more accurately the reservoirs of carbon from the core, where iron may bind large amounts of carbon, through the mantle where convective cells may carry it upward to the crust which traps the reservoirs that are most familiar to humanity. While some crustal reservoirs may be "biotic," that is, formed from formerly living matter that is buried and cooked in the crust, it is now clear that Earth also contains much larger amounts of abiotic carbon, part of the primordial rock and gas at the planet's origins. Improving estimates of fluxes would be the second major focus of the Deep Carbon Observatory. The third focus would be the origins and synthesis of the particular chemical forms that carbon takes, including methane, which the high pressures and temperatures at great depths make possible. The fourth focus would be deep life. Humanity has never drilled deeper than life. The mud recovered from the deepest holes contains microbes. Geobiologists conjecture that the weight of the "deep hot biosphere" may rival the weight of the surface biosphere. The strategy of the Deep Carbon Observatory proposal draws on experiences of the Digital Sky Survey, Census of Marine Life, and other Sloan science initiatives. Success will depend on development of innovative instruments for working at very high pressures and temperatures. Success will also depend on high leveraging of Sloan funds: the CIW proposal aims to reach $50 million in additional commitments within three years. The leaders of the effort-Robert Hazen, a geologist and superb communicator with broad interests including biology, and Russell Hemley, a top expert in high-pressure instrumentation-have strong worldwide networks and propose the Deep Carbon Observatory with enormous excitement. The highly respected President of the Carnegie Institution of Washington, Richard Meserve, former chair of the Nuclear Regulatory Commission, has participated directly in the project development and pledged Carnegie's own assets to the effort.