Ground-based Ida model: comparison with the first Galileo image

In this paper we present a model of the shape and surface features of the asteroid 243 Ida, second fly-by target of the Galileo mission. We obtained this model by applying the lightcurve inversion method (Fulchignoni and Barucci, B.A.A.S. 20, 866, 1988), already used for the model of 951 Gaspra (Barucci et al., Astron. Astrophys. 266, 385–394, 1992), on the whole sample of available lightcurves obtained during five oppositions between 1984 and 1993 (Binzel, Icarus 72, 135–208, 1987; Gonano-Beurer et al., Astron. Astrophys. 254, 393–396, 1992; Binzel et al., Icarus 105, 310–325, 1993; Mottola et al., Planet. Space Sci. 42, 21–25, 1994). The comparison of our model with the first Galileo image of 243 Ida gives another “ground truth” for the used method based on observations from the Earth.