太空风化对硅酸盐小行星反射光谱的影响  

The Influence of Space Weathering on the Reflectance Spectra of Silicate Asteroids

作　　者：张沁葳 张鹏飞 王鹏越 姜特 卢瑜 韩慧杰 庞荣华 李阳[3] 张昊[5] 金岩 吴昀昭 ZHANG Qin-wei;ZHANG Peng-fei;WANG Peng-yue;JIANG Te;LU Yu;HAN Hui-jie;PANG Rong-hua;LI Yang;ZHANG Hao;JIN Yan;WU Yun-zhao(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026;Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081;State Key Laboratory of Lunar and Planetary Sciences,Macao Unitersity of Science and Technology,Macao 999078;Planctary Science Institute,China University of Geosciences,Wuhan 430074;Earth Obseruation System and Data Center,China National Space Administration,Beijing 100101)

机构地区：[1]中国科学院紫金山天文台,南京210023 [2]中国科学技术大学天文与空间科学学院,合肥230026 [3]中国科学院地球化学研究所,贵阳550081 [4]澳门科技大学月球与行星科学国家重点实验室,中国澳门999078 [5]中国地质大学行星科学研究所,武汉430074 [6]国家航天局对地观测与数据中心,北京100101

出　　处：《天文学报》2024年第6期121-134,共14页Acta Astronomica Sinica

基　　金：国家国防科技工业局空间碎片与小行星专项(KJSP2023020105)资助。

摘　　要：太空风化研究对小行星表面环境及成分遥感反演具有重要意义.目前对太空风化引起小行星光谱变化的研究结果并不统一,对硅酸盐小行星风化模式缺乏统一的认识.基于大样本研究的思路,统计了4颗普通球粒陨石(H、L和LL型)、7种硅酸盐单矿物、6组橄榄石-辉石不同比例混合物的激光辐照实验,分析辐照前后样品可见-近红外反射光谱(0.45–2.5μm)的变化,并结合小行星光谱研究太空风化对硅酸盐小行星光谱的影响.结果显示,太空风化不会引起1μm吸收中心的明显偏移,但会导致吸收面积比(2μm带面积/1μm带面积)增加.因此,使用“1μm吸收中心–吸收面积比”作图来区分陨石类型仍然有效,即太空风化对矿物学分类影响较小.在主成分分析图中, A型小行星具有几乎平行于α线的风化趋势,其余硅酸盐小行星具有“Q-Sq-S”的风化趋势.基于斯隆数字巡天数据(Sloan Digital Sky Survey dataset, SDSS)的小行星分类系统会混淆富含橄榄石小行星的分类,并可能低估A型小行星的数量.系统分析了硅酸盐小行星太空风化模式及光谱变化规律,对深入认识小行星光谱的太空风化效应以及矿物定量遥感反演具有实用价值.Research on space weathering is of great significance for the remote sensing inversion of the surface environment and composition of asteroids.Currently,the research results on the spectral changes of asteroids caused by space weathering are not consistent,and there is a lack of systematic understanding of the weathering models of silicate asteroids.In this study,based on the idea of large-sample research,laser irradiation experiments were conducted on 4 ordinary chondrites(H,L,and LL types),7 types of silicate minerals,and 6 groups of olivine-pyroxene mixtures with different proportions.The visiblenear-infrared reflectance spectra(0.45-2.5μm)of the samples before and after laser experiments were analyzed,and the impact of space weathering on the reflectance spectra of silicate asteroids was studied in combination with the spectral classification of asteroids.Our results showed that space weathering can increase the band area ratio,but it does not cause a significant shift in the 1μm absorption center.The use of the"1μm absorption center-band area ratio"diagram is still effective in distinguishing different types of meteorites.Moreover,space weathering has little impact on overall mineralogical classification.In the principal component analysis plot,A-type asteroids have a space weathering trend almost parallel to theαline,while the rest of the silicate asteroids have a"Q-Sq-s"space weathering trend.The asteroid classification system based on Sloan Digital Sky Survey(SDSS)data may confuse the classification of olivine-rich asteroids and may underestimate the number of A-type asteroids.This study systematically analyzed the weathering models and spectral changes of silicate asteroids,which is scientifically significant for a better understanding of the space weathering effect on asteroid spectra and has practical value for remote sensing quantitative inversion.

关 键 词：行星和卫星:表面 月球 小行星:普通 

分 类 号：P185[天文地球—天文学]