Spectral properties of the surface reflectance of the northern polar region of Mercury  

作　　者：Nguyen Bich Ngoc Nicolas Bott Pham Ngoc Diep 

机构地区：[1]Department of Astrophysics,Vietnam National Space Center,Vietnam Academy of Science and Technology,18 Hoang Quoc Viet,Cau Giay,Hanoi,Vietnam [2]Laboratoire d'Etudes Spatiales et d' Instrumentation en Astrophysique,l'Observatoire de Paris,5 place Jules Janssen 92195 Meudon,France

出　　处：《Research in Astronomy and Astrophysics》2020年第3期92-107,共16页天文和天体物理学研究（英文版）

基　　金：Financial support from Centre National E.Etudes Spatiales(CNES),USTH is gratefully acknowledged.

摘　　要：We analyze MESSENGER reflectance measurements covering the northern polar region of Mercury,the least studied region of the northern mercurian hemisphere.We use observations from the Mercury Dual Imaging System Wide-Angle Camera(MDIS/WAC)and the Mercury Atmospheric and Surface Composition Spectrometer(MASCS/VIRS)to study the spectral dependence of the surface reflectance.The results obtained from the observations made by both instruments are remarkably consistent.We find that a second degree polynomial description of the measured reflectance spectra gives very good fits to the data and that the information that they carry can best be characterized by two parameters,the mean reflectance and the mean relative spectral slope,averaged over the explored range of wavelengths.The properties of the four main types of terrains known to form Mercury’s regolith in the northern region,smooth plains(SPs),heavily cratered terrain(HCT),fresh ejecta/materials and red pitted ground(RPG),are examined in terms of these two parameters.The results are compared,and found consistent with those obtained by earlier studies in spite of difficulties met in obtaining accurate reflectance measurements under the large incidence angle condition characteristic of polar regions.These results will help with the preparation of the BepiColombo mission and with supporting its observational strategy.We analyze MESSENGER reflectance measurements covering the northern polar region of Mercury, the least studied region of the northern mercurian hemisphere. We use observations from the Mercury Dual Imaging System Wide-Angle Camera(MDIS/WAC) and the Mercury Atmospheric and Surface Composition Spectrometer(MASCS/VIRS) to study the spectral dependence of the surface reflectance. The results obtained from the observations made by both instruments are remarkably consistent.We find that a second degree polynomial description of the measured reflectance spectra gives very good fits to the data and that the information that they carry can best be characterized by two parameters, the mean reflectance and the mean relative spectral slope, averaged over the explored range of wavelengths.The properties of the four main types of terrains known to form Mercury’s regolith in the northern region,smooth plains(SPs), heavily cratered terrain(HCT), fresh ejecta/materials and red pitted ground(RPG), are examined in terms of these two parameters. The results are compared, and found consistent with those obtained by earlier studies in spite of difficulties met in obtaining accurate reflectance measurements under the large incidence angle condition characteristic of polar regions. These results will help with the preparation of the BepiColombo mission and with supporting its observational strategy.

关 键 词：planets and SATELLITES terrestrial planets-planets and SATELLITES surfaces-techniques SPECTROSCOPIC 

分 类 号：P185.1[天文地球—天文学]