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 period comet 46P/Wirtanen and the asteroids 140 Siwa and 4979 Otawara. However, due to problems with the Ariane V launcher, the launch was postponed and the European Space Agency had to identify new mission targets, suitable for a launch window at the end of February 2004. The short period comet 67P/Churyumov- Gerasimenkowaschosenasprimarytargetforthenewbaseline, together with one or two asteroids to be selected, depending on the ?v available after the Rosetta probe interplanetary orbit insertion. After the succe- ful launch of the mission on March 2nd, 2004, the new baseline foresees a double ?y-by with asteroids 21 Lutetia and 2867 Steins, on the way towards the rendezvous with the primary target, that will be reached in 2014. The papers included in this volume cover di?erent complementary ?elds: observations of the new Rosetta targets, laboratory experiments, theoreticalsimulationofcometenvironmentandprocesses,performances of the experiments on board Rosetta spacecraft, also in view of the new mission target(s). Afterthepostponementofthemissionlaunch,comet67P/Churyumov- Gerasimenko was the subject of an intense observation campaign, - tween February and June 2003.

Discovery, Observations and Investigations of Comet 67P/Churyumov-Gerasimenko in Kyiv.- Monitoring Comet 67P/Churyumov-Gerasimenko from ESO in 2003.- CO and Dust Productions in 67P/Churyumov-Gerasimenko at 3 AU Post-Perihelion.- The Dust Activity of Comet 67P/Churyumov-Gerasimenko.- Observations of Comet 67P/Churyumov-Gerasimenko with the International Ultraviolet Explorer at Perihelion in 1982.- Observations of the New Rosetta Targets.- Water Production Rate of Comet 67P/Churyumov-Gerasimenko.- Rosetta Asteroid Candidates.- Characterizing 21 Lutetia with its Reflectance Spectra.- Detection of Parent Molecules in Comets using UV and Visible Spectroscopy.- Grain Sizes of Ejected Comet Dust. Condensed Dust Analogs, Interplanetary Dust Particles and Meteors.- Physical Properties of Cometary Dust. The Case of Churyumov-Gerasimenko.- Physical Model of the Coma of Comet 67P/Churyumov-Gerasimenko.- The Dust Environment of Comet 67P/Churyumov-Gerasimenko.- Modelling the Environment of 67P/Churyumov-Gerasimenko.- Plasma Environment of Comet Churyumov-Gerasimenko - 3D Hybrid Code Simulations.- Modelling of the Structure and Light Scattering of Individual Dust Particles.- Gas and Dust Activity of the Nucleus of 67P/Churyumov-Gerasimenko: Some Preliminary Results.- Big Particle Emission from Comet 67P/Churyumov-Gerasimenko.- The Solar Wind Removal of Volatiles from Comets - Perspectives on the Rosetta Mission.- Non-Resonant Gravitational Motion and Equilibrium Stability of Rosetta.- Virtis Experiment at Churyumov - Gerasimenko Comet, New Rosetta Target.- Consert Experiment: Description and Performances in View of the New Target.- Rosina's Scientific Perspective at Comet Churyumov-Gerasimenko.- The Giada Experiment for the Rosetta Mission.- Implications of the New TargetComet on Science Operations for the Rosetta Lander.- First Contact with a Comet Surface: Rosetta Lander Simulations.- The Rosetta Lander Experiment Sesame and the New Target Comet 67P/Churyumov-Gerasimenko.