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Materials and Surface Processes at Gale Crater and the Moons of Mars Derived from High Spatial and Spectral Resolution Orbital Datasets.

机译：来自高空间和光谱分辨率轨道数据集的大风火山口和火星卫星的材料和表面过程。

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摘要

This thesis is a collection of studies that use orbital remote sensing data to investigate the composition and geologic histories of Mars' moons, Phobos and Deimos, and Mt. Sharp, the destination for the Curiosity Mars rover. A final chapter focuses on Curiosity data and terrestrial analog studies to supplement orbital predictions about Mt. Sharp.;Disk-resolved hyperspectral observations of Phobos acquired at a range of lighting and viewing geometries are fit with a Hapke photometric function to solve for the single particle phase function and single scattering albedos of Phobos and also disk-resolved hyperspectral observations of Deimos. Fe2+ electronic absorptions diagnostic of olivine and pyroxene are not detected. A broad absorption centered on 0.65 microm within the red spectral units of both moons is seen, and this feature is also evident in telescopic, Pathfinder, and Phobos-2 observations of Phobos. A 2.8 &mgr;m metal-OH combination absorption on both moons is also detected, and this absorption is shallower in the Phobos blue unit than in the Phobos red unit and Deimos. The strength, position, and shape of both absorptions are similar to features seen on low-albedo primitive asteroids. Two end-member hypotheses could explain these spectral features: the presence of highly desiccated Fe-phyllosilicate minerals indigenous to the bodies, or Rayleigh scattering and absorption of small iron particles formed by exogenic space weathering processing, coupled with implantation of H from solar wind. Phobos' and Deimos' low reflectances, lack of mafic absorption features, and red spectral slopes are incompatible with even highly space weathered chondritic or basaltic compositions. These results, coupled with similarities to laboratory spectra of Tagish Lake (possible D-type asteroid analog) and CM carbonaceous chondrite meteorites, show that Phobos and Deimos have primitive compositions. If the moons formed in situ rather than by capture of primitive bodies, primitive materials must have been added to the Martian system during accretion or a late stage impact.;Oversampled visible/near-infrared hyperspectral data over Mt. Sharp in Gale Crater are used to generate spatially sharpened maps of the location of red crystalline hematite within the uppermost stratum of a ~6.5 km long ridge on the mound's northern flank. Emplacement of the hematite is hypothesized to result either from exposure of anoxic Fe+2-rich groundwater to an oxidizing environment or from in place weathering of precursor silicate materials under oxidizing conditions. Although at the time of writing the rover is still ~6 km north of the ridge, high resolution color imaging and low resolution spectral remote sensing data of the ridge collected by Curiosity are consistent with orbital observations. When Curiosity does arrive at the ridge, it is well equipped to distinguish between predicted end-member textural scenarios for ridge materials, which will be essential to understand its formation and evolution.
机译：本文是使用轨道遥感数据研究火星卫星，火卫一和地摩斯以及山的组成和地质历史的研究的集合。夏普，好奇号火星探测器的目的地。最后一章侧重于好奇心数据和地面模拟研究，以补充有关Mt的轨道预测。在一系列照明和观察几何条件下获取的火卫一的磁盘分辨高光谱观测结果与Hapke光度函数相匹配，以解决火卫一的单相相位函数和单散射反照率，以及Deimos的磁盘分辨高光谱观测结果。未检测到橄榄石和辉石的Fe2 +电子吸收诊断。在两个卫星的红色光谱单位内，可见到以0.65微米为中心的宽吸收，并且在望远镜，探路者和Phobos-2的火卫一观测中也很明显地看到了这一特征。在两个卫星上也检测到2.8μm的金属-OH组合吸收，并且在Phobos蓝单元中的吸收比在Phobos红单元和Deimos中的吸收要浅。两种吸收的强度，位置和形状类似于在低反照率原始小行星上看到的特征。两个末端成员假说可以解释这些光谱特征：存在于人体中的高度干燥的Fe-页硅酸盐矿物，或者是外源性风化过程形成的瑞利散射和吸收的小铁颗粒，再加上太阳风中注入的H。 Phobos和Deimos的反射率低，缺乏镁铁矿吸收特征，红色光谱斜率甚至与高度空间风化的软骨或玄武岩成分也不相容。这些结果，再加上塔吉什湖（可能是D型小行星类似物）和CM碳质球粒陨石的实验室光谱的相似性，表明火卫一和Deimos具有原始成分。如果卫星是在原地形成而不是通过捕获原始物体形成的，则必须在增生或后期撞击过程中将原始材料添加到火星系统中；对Mt的可见/近红外高光谱数据进行过采样。 Gale Crater中的Sharp（尖锐）用于生成红色结晶赤铁矿位置的空间锐化图，该红色结晶赤铁矿位于土丘北侧〜6.5 km长的山脊的最上层。据推测，赤铁矿的沉积是由于富Fe + 2的缺氧地下水暴露于氧化环境，或者是前体硅酸盐材料在氧化条件下原位风化所致。尽管在撰写本文时，流动站仍位于山脊以北约6公里处，但好奇号收集的山脊的高分辨率彩色成像和低分辨率光谱遥感数据与轨道观测一致。当好奇心确实到达山脊时，它就可以很好地区分山脊材料的预测的端构件纹理方案，这对于理解其形成和演化必不可少。

著录项

  • 作者

    Fraeman, Abigail Ann.;

  • 作者单位

    Washington University in St. Louis.;

  • 授予单位 Washington University in St. Louis.;
  • 学科 Planetology.;Remote Sensing.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 149 p.
  • 总页数 149
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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