硅质小行星矿物定量反演研究  

Quantitative Inversion of Siliceous Asteroid Minerals

作　　者：黄小桐 黄海涛 雷开宇 华宝成[4] 王立[4] 吴昀昭[1,2] 李彦昭 徐天弈 卢瑜 HUANG Xiaotong;HUANG Haitao;LEI Kaiyu;HUA Baocheng;WANG Li;WU Yunzhao;Li Yanzhao;XU Tianyi;LU Yu(State Key Laboratory of Lunar and Planetary Sciences,Macao University of Science and Technology,Macao 999078,China;Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China;School of Astronomy and Space Sciences,University of Science and Technology of China,Hefei 230026,China;Beijing Institute of Control Engineering,China Academy of Space Technology,Beijing 100190,China)

机构地区：[1]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 [2]中国科学院紫金山天文台,南京210023 [3]中国科学技术大学天文与空间科学学院,合肥230026 [4]中国空间技术研究院北京控制工程研究所,北京100190

出　　处：《空间科学与试验学报》2024年第4期1-9,共9页Journal of Space Science and Experiment

基　　金：国家重点研发计划项目(2023YFE0109900);国家自然科学基金(12150009);光电测量与智能感知中关村开放实验室开放基金(LabSOMP-2024-04)。

摘　　要：了解小行星的物质组成对小行星起源与演化研究、太空资源利用以及小行星防御等都具有重要指导作用。硅质小行星是近地以及内主带小行星的主要类型,也是最常见陨石普通球粒陨石的母体。为了增进对硅质小行星矿物成分的认识,本文研究了光谱信噪比较高的8颗硅质小行星的矿物组成。通过对小行星混合光谱进行去卷积获得铁镁质矿物吸收特征,得到它们的镁橄榄石指数(Fo#)以及高钙辉石占比,并获得了小行星对应的陨石类似物。研究发现,Sr型小行星(3)Juno、(808)Merxia和S型小行星(4197)Morpheus具有较高的Fo#和较低的高钙辉石含量,成分类似于H球粒陨石。Sq型小行星(433)Eros具有相对低的Fo#和较高的高钙辉石占比,其成分类似于L球粒陨石。Sv型小行星(5)Astraea和S型小行星(17)Thetis与V型小行星(3908)Nyx和(4055)Magellan表面几乎不含橄榄石,这4颗小行星的矿物成分与玄武质无球粒陨石类似。本研究表明即便都是具有明显吸收特征的硅质小行星,它们的类型也具有矿物多样性,对应的陨石类型复杂多样。这既反映了小行星自身起源演化以及后期太空风化、冲击变质的影响,也说明了现有小行星光谱分类体系有待改进,在基于光谱解译小行星矿物组成及演化时需要谨慎。Understanding the components of asteroids plays an important role in guiding research on the origin and evolution of asteroids,utilization of space resources,and asteroid defense.Siliceous asteroids are the main type of nearEarth and inner main belt asteroids and are also the most common parent bodies of ordinary chondrite.In order to improve our understanding of the mineral composition of siliceous asteroids,the mineral compositions of eight siliceous asteroids with high spectral signal-to-noise ratios were investigated.By deconvolving the mixed spectrum of asteroids,we have obtained the absorption characteristics of ferromagnesian minerals,including their magnesium olivine index(Fo#)and the proportion of high-calcium pyroxene and then we identified the corresponding meteorite analogues for these asteroids.The results indicate that Sr-type asteroids(3)Juno,(808)Merxia and S-type asteroid(4197)Morpheus have higher Fo#and lower high-calcium pyroxene content,with surface compositions similar to H chondrites.The Sq-type asteroid(433)Eros has a relatively low Fo#and a high proportion of high-calcium pyroxene,with surface compositions resembling L chondrites.Sv-type asteroid(5)Astraea and S-type asteroid(17)Thetis have surfaces almost devoid of olivine,while V-type asteroids(3908)Nyx and(4055)Magellan lack olivine altogether,with surface mineral compositions similar to basaltic achondrites.The results show that even if they are all siliceous asteroids,their types have mineral diversity,and their correspondence with meteorite types is also complex and diverse.This is related to the origin and evolution of the asteroid itself and its later transformations such as space weathering and impact metamorphism.It also shows that the existing asteroid spectral classification system needs to be improved,and caution is needed when interpreting the mineral composition and evolution of asteroids based on spectra.

关 键 词：小行星 光谱 矿物 修正高斯模型 定量反演 

分 类 号：P185[天文地球—天文学]