The origin of the atmosphere / Tobias C. Owen -- The early atmosphere as a source of biogenic compounds / James F. Kasting and Lisa L. Brown -- The endogenous synthesis of organic compounds / Stanley L. Miller -- Hydrothermal systems / Nils G. Holm and Eva M. Andersson -- Cosmic origin of the biosphere / Armand H. Delsemme -- Clues from the origin of the Solar System: meteorites / John R. Cronin -- Micrometeorites on the early Earth / Michel Maurette -- Membrane compartments in prebiotic evolution / David W. Deamer -- Origin of life in an iron-sulfur world / Günter Wächtershäuser -- Clues from present-day biology: the thioester world / Christian de Duve -- Origins of the RNA world / Alan W. Schwartz -- Catalyzed RNA synthesis for the RNA world / James P. Ferris -- Catalysis in the RNA world / Kenneth D. James and Andrew D. Ellington -- Self-replication and autocatalysis / Jens Burmeister -- Hyperthermophiles and their possible role as ancestors of modern life / Karl O. Stetter -- Tracing the roots of the universal tree of life / J. William Schopf -- Titan / François Raulin -- Life on Mars / Christopher P. McKay.