题 目：Mapping the Dwarf World - Ceres and Vesta – Preparing for Dawn Mission

报告人：Dr. Li Jian-yang

(Department of Astronomy，University of Maryland）

摘 要:

Ceres and Vesta are the two largest asteroids in the Main Asteroid Belt, and represent the very early stage of the formation of terrestrial planets, and possibly the core of giant planets. Therefore by studying their formation and evolutionary history, we are studying the embryo stages of the formation of the planetary system. NASA's Dawn mission will visit and rendezvous with both of them in 2011 and 2015, respectively. We used spatially resolved images of these two asteroids collected by Hubble Space Telescope at multiple wavelengths to construct the surface albedo maps, and to study their surface mineralogical features and compositions. I will introduce the Dawn mission, discuss the background and current status of understanding the physical properties and status of these two asteroids, present their global maps, offer some interpretations of their surface mineralogical compositions, and discuss their formation and evolutionary history. The implications to the formation and early stage of terrestrial planets will also be discussed.

时 间：2009年4月7日上午10:00

地 点：（北京西路2号）紫台大楼327教室

紫金山天文台学术委员会学术交流工作委员会

2009年4月2日