46P/Wirtanen: necessary observations in support of ROSETTA

Knowledge of some basic properties of comet 46P/Wirtanen is vital for the successful design and execution of the International Rosetta Mission. Specific observations to study the comet nucleus and its gas and dust environment in detail are strongly requested during its forthcoming apparition. 46P/Wirtanen should be regularly monitored along its orbit by means of imaging and spectroscopy at different wavelengths ranging from UV to radio emission. Information should be retrieved on the nucleus (size, shape, rotation, gross surface topography), the gas and dust coma (near-nucleus morphology, composition, evolution), the cometary activity (onset of activity, gas and dust production rates as a function of heliocentric distance) and astrometric positions. An overview is given of the ground-based observations needed in support of ROSETTA and the observational opportunities in 1996/97.