This volume collects papers presented, as invited and contributed talks or posters, at the workshop on "The NEW Rosetta targets. Obs- vations, simulations and instrument performances," which was held in CaprionOctober13-15,2003. Morethan100scientistscoveringdi?erent ?elds, such as optical and radio astronomy, laboratory experiments and modelling of comet physics and processes, as well as several Principal Investigators of the instruments on board Rosetta, participated to this highly interdisciplinary workshop. The Rosetta mission was programmed for launch in January 2003 towards the short...