Title: Dawn at Vesta: A Whole New World
　  Speaker：Jian-Yang Li, Planetary Science Institute(NASA)
　  Time: May15th, 2012 (Tuesday),9:30AM
　  Location: Mid conf. room, 3rd floor

Abstract：
　　 Asteroids, as both the building blocks of and leftovers from the formation of our planetary system, retain important information about the processes of planet ormation. Vesta is one of the largest asteroids, representing the early stage of terrestrial planet formation and the transition from planetesimals to a full-sized planet. Dawn pacecraft currently in orbit around Vesta returned a huge amount of multispectral imaging and spectroscopic data in the visible and near-infrared wavelengths at a scale as high as 20 m/pix, substantially expanding our knowledge about Vesta.
　　 Dawn data provide high-precision measurement of the basic properties of Vesta including its shape and gravity, and constrain its internal structure. Vesta displays extremely large variations on its albedo, color, and spectra across the surface, a result of its complicated impacthistory. Vesta, as seen by Dawn, is a unique world full of surprises in many aspects.