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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.07.047 Byline: BenoA[R]t Carry (a)(b), Pierre Vernazza (c), Christophe Dumas (b), Marcello Fulchignoni (a) Keywords: Asteroid vesta; Asteroids, Surfaces; Adaptive optics; Infrared observations Abstract: Vesta, the second largest Main-Belt Asteroid, will be the first to be explored in 2011 by NASA's Dawn mission. It is a dry, likely differentiated body with spectrum suggesting that is has been resurfaced by basaltic lava flows, not too different from the lunar maria. Here we present the first disk-resolved spectroscopic observations of an asteroid from the ground. We observed (4) Vesta with the ESO-VLT adaptive optics equipped integral-field near-infrared spectrograph SINFONI, as part of its science verification campaign. The highest spatial resolution of [approximately equal to]90km on Vesta's surface was obtained during excellent seeing conditions (0.5.sup.a[sup.3]) in October 2004. We observe spectral variations across Vesta' surface that can be interpreted as variations of either the pyroxene composition, or the effect of surface aging. We compare Vesta's 2[mu]m absorption band to that of howardite-eucrite-diogenite (HED) meteorites that are thought to originate from Vesta, and establish particular links between specific regions and HED subclasses. The overall composition is found to be mostly compatible with howardite meteorites, although a small area around 180[degrees]E longitude could be attributed to a diogenite-rich spot. We finally focus our spectral analysis on the characteristics of Vesta's bright and dark regions as seen from Hubble Space Telescope's visible and Keck-II's near-infrared images. Author Affiliation: (a) LESIA, Observatoire de Paris-Meudon, 5 Place Jules Janssen, 92195 Meudon Cedex, France (b) ESO, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago de Chile, Chile (c) Research and Scientific Support Department, European Space Agency, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands Article History: Received 24 July 2008; Revised 13 July 2009; Accepted 31 July 2009 Article Note: (footnote) [star] Based on observations collected at the European Southern Observatory, Paranal, Chile - 60.A-9041.