报告题目：Unveiling a Mysterious World–Dawn arrives at Ceres

　　报 告 人：Dr. Jian-Yang Li （Planetary Science Institute, USA）

　　摘    要：Dawn spacecraft entered the first science orbit around Ceres in late April 2015, starting its yearlong mapping activity of this mysterious world. Ceres, as the largest object located near the water ice-line in the current solar system, could hide clues about water transportation shaping the habitable Earth, as well as the process of the formation of outer solar system planets and icy satellites. It may also holds secrets of the new category of objects in the asteroid belt that are actively outgassing, the so-called Main-Belt Comets. However, little is known about Ceres after more than 200 years since its discovery, due primarily to its nearly featureless visible-infrared spectrum and lack of meteorite analogues. Since approach, Dawn spacecraft has collected images of Ceres with resolutions down to 400 m/pixel so far. Many spectacular features on the surface have been identified, such as bright spots, large scale lineaments, relaxed basins, and mysterious mons, all much more interesting than one could ever expect. The study of Ceres is just beginning.I will briefly introduce the background of Ceres, and discuss some early images of interesting surface features.

　　时    间：2015年7月31日 星期五 上午10:00

　　地    点：（北京西路2号）紫台大楼517会议室

　　联 系 人：董瑶（83332059）

欢迎大家积极参加！

　                                          　紫金山天文台学术委员会