Life on other planetsWhite Paper for the NSF-NASA-DOE Astronomy and Astrophysics Advisory Committee Exoplanet Task ForcePeter Roderick Lawson, Oliver Peter Lay, Kenneth John Johnston, Charles Arnold Beichman, Stephen C. Unwin, Stefan R. Martin, Sarah L. Hunyadi, Olivier Absil, Rachel L. Akeson, John Bally, Pascal Bordé, David E. Crisp, William C. Danchi, Denis Defrère, Carlos Eiroa, Paul G. Falkowski, Thomas Henning, Philip M. Hinz, Jan M. Hollis, David C. Hyland, Lisa Kaltenegger, Lucas Labadie, Benjamin F. Lane, Gregory P. Laughlin, Alain Léger, Rene Liseau, Dimitri Mawet, Bertrand Mennesson, John D. Monnier, Alice C. Quillen, Huub J. A. Röttgering, Franck Selsis, Eugene Serabyn, David James Wilner, Neville J. Woolf, Wesley Arthur Traub, Robert O. Gappinger, Alexander A. Ksenzov, Robert D. Peters, Daniel P. Scharf, United States. National Aeronautics and Space Administration, Jet Propulsion Laboratory (U.S.)