Polar Water Ice Deposits:

The Contrast Between Mercury and the Moon

極區水冰沉積：水星與月球的對比

主講人：David T. Blewett研究員

Johns Hopkins University Applied Physics Lab, USA

時間：2017年8月29日，上午10:00 – 11:30

地點：遙感樓517會議室

摘要：The Moon and Mercury both have relatively small obliquity (tilts of the rotation axis). As a result, low-elevation areas near the poles may be in permanent shadow, and hence have experienced very low temperatures over long periods of time. The conditions in these cold traps are suitable for accumulation of volatile compounds, including water ice. A variety of remote-sensing datasets indicate that ice is indeed present at the lunar and mercurian poles. I will review evidence for ice that comes from Earth-based radar, mapping of polar shadows, neutron spectrometry, temperature modeling and mapping, and albedo mapping. There are important differences between the characteristics of the polar deposits on Mercury and those on the Moon that suggest differing histories of delivery of volatiles to the two worlds.

報告人簡介：David T. Blewett is a member of the Principal Professional Staff in the Planetary Exploration Group at the Johns Hopkins University Applied Physics Laboratory in Maryland, USA. He was a member of the science team for the NASAMESSENGERMercury orbiter mission. He was also a member of theDawnscience team for the Vesta phase of the mission. His research interests are planetary surface processes, space weathering, remote sensing, and reflectance spectroscopy. He received a bachelor's degree in astronomy and astrophysics from the University of Pennsylvania, and master's and Ph.D. degrees (geology and geophysics) from the University of Hawaii.