月震与月球内部结构

阿波罗（Apollo）登月计划在月球表面上布设的月震仪为探索月球内部结构提供了极佳资料来源,本文综述了近年来对月震资料的分析及利用月震资料研究月球内部结构的相关研究结果。月震仪记录到的振动信号主要分为天体撞击、月震和局域震动三类。天体撞击又分为流星体撞击和人造天体撞击,其震源位于月球表面。月震按震源深度分布分为浅源月震与深源月震,前者的震源深度大约为50～220km,释放的能量较大但发生次数较少,记录信号以高频成分为主;后者的震源深度大约为700～1150km,并具丛集性,与潮汐应力有关。局域震动在月球日出与日落时出现,被认为是由近月表的热破裂和变形过程所产生。月球内部结构的多数研究集中于月震仪下方月壳厚度计算及上月幔一维速度模型的建立。结果表明月壳平均厚度大约为40km,而不是早期研究得到的60km左右;通过现有的月震资料还不能得到月球下月幔、月核、月球深部间断面的相关信息。文章最后对月球内部的进一步研究做了总结和展望。     

月震重定位

由于前人的月震定位结果主要是基于20世纪70、80年代的月球速度模型, 定位结果误差较大, 无法为月震层析成像等研究提供精确的月震参数.随着对月球内部结构研究的不断深入, 月球速度模型及分层结构的精细程度已经有了很大提高.通过对Apollo月震数据解码及分析, 重新拾取了月震初至数据, 在总结前人震源定位的基础上, 利用月球新近速度模型, 采用Geiger震源定位方法进行了月震震源定位, 给出了较为全面的月震参数目录, 并对月震和地震的分布及形成机制进行了对比, 可为以后月震及月球内部结构的深入研究提供更多的依据.      

月震学

还是在50年代末,美国制定了阿波罗(Apollo)月球登陆探测计划,从此对月球研究进入了一个新纪元。开始时,在探测器中安置了测震仪,测量它在月球表面着陆时的冲击效应,随后在发射阿波罗11、12、14、15及17时,分别在月球表面上安置了测震仪,对月球震动进行直接测量,测量的内容也随之扩大,不单测量后续的探测器着落时的冲击效应,而且还测量月球中发生的其它的震动现象。短短的几年时间里,积累了不少月球上的震动记录,逐渐形成了一门独特的研究领域——月震学。     

月球矿产资源勘查进展及展望

地球是人类起源和成长的"摇篮",然而人类终将跳出"摇篮",拥抱更广阔的宇宙空间。月球是地球唯一的天然卫星,也是唯一一颗人类已经登陆的地外星球,月球矿产资源开发利用是人类走向太空的必经之路。前苏联Luna计划和美国Apollo计划引领的第一次探月高潮,采回了约382kg样品使人类得以近距离接触和全方位认识月球。当前正是全球探月工程的第二次高潮期,在本次探月高潮期,月球矿产资源的开发利用将成为重要目标。以往的月球资源探测以科学研究为主,而以应用和商业利益为目的的月球资源勘查工作尚未开展。因此,有必要对月球矿产资源进行系统梳理和研究,初步建立月球矿产勘查的规范,指导载人登月和人机互动进行月面资源勘查。本文从国际太空矿产领域的发展趋势、月球矿产资源的需求、潜在的矿产种类、勘查流程等方面进行系统综述,根据可勘查属性将月球各类矿产划分为钛铁矿型、斜长岩型、磷酸盐型、月壤型、水冰型等5种类型,为中国未来的载人探月项目着陆区选址和矿产勘查规范的建立提供初步参考依据。     

月壤厚度的研究方法与进展

月壤厚度的研究对未来月球探测、登月与月球资源开发均具有十分重要的意义。它是恢复月球起源和演化历史的重要参数,也是估算月球3He资源量的必要前提。本文将月壤厚度的研究方法归纳为直接和间接两类,直接方法主要是利用月震数据对月壤厚度进行推算,间接方法包括基于撞击坑形态、分布以及地基雷达遥感数据估算月壤厚度两种。随着定量微波遥感的发展,结合我国嫦娥探月工程的实施,利用高分辨率被动微波遥感亮温反演月壤厚度为月壤厚度的研究指出一个新的方向。     

嫦娥五号返回样品的科学研究前景

深空探测是国家综合国力的集中体现,也是各航天大国科技竞争的制高点。自2007年嫦娥探月工程顺利实施以来,我国已经成为全球第二次探月热潮里的中坚力量。嫦娥五号采样工程的成功,使人类在间隔44年后再一次获得来自月球的珍贵样品,标志着中国探月工程上了更高的台阶。海量探测数据的获取和月球样品的返回,将为月球形成演化等重大科学问题的研究提供新的视角与支撑。放眼未来,我国月球极区探测、载人登月和月球科研站建设已经列入规划,工程探测和科学研究的目标已从“认识月球”逐步向“开发月球”“利用月球”转变。对于月球土壤样品的研究,中国科学院地球化学研究所具有良好的基础,曾对来自Apollo的月壤样晶进行过详细的研究,本次针对嫦娥五号样品,该所承担了月壤特性及其形成演化历史等方面的研究工作。为让广大科技工作者和社会公众了解这一工作进展,本刊特邀地球化学所李阳博士撰文介绍相关情况,后续工作本刊还将进行跟踪报道。     

月球重力场研究的论述

月球重力场探测是了解月球内部结构构造最有效的手段之一,也是未来登陆点选择的重要依据.在众多方法中,卫星重力探测是进行全月球覆盖以及获得月球深部信息的重要方法.本文叙述了当前月球重力探测历史和重力模型发展过程,并对这些模型进行比较分析.在了解前沿研究方法的基础上讨论了月球重力位场解算的基本原理、高精度月球重力场获得的方法...     

月球重力场研究及其应用进展

月球重力场研究及相关应用是月球科学探测中的重要内容之一。本文回顾了月球重力测量及月球重力场模型、月球地形模型等主要研究进展,总结了月球重力场（包括地形）在月球内部结构研究,特别是在月壳结构以及月球质量瘤等方面取得的研究成果。此外,月球重力场还应用于月幔／月核研究、月球均衡状态、月球物质成分及月球演化历史的研究中。随着我国嫦娥探月计划的实施,利用其探测数据建立自主重力场模型及地形模型成为我国探月研究的基础工作之一。在此基础上可开展月壳结构、月球均衡状态、月球质量瘤及月壳成分等研究,同时借鉴地球科学中相关学术思想和方法技术,从而促进对月球及类地行星等结构的研究。     

我国月球探测的总体科学目标与发展战略

在简述月球探测的历程与趋势的基础上,强调当代月球探测的总体目标为：①研究月球与地月系的起源和演化,特别是月球大气层与磁场的消失,矿物与岩石的分布和形成环境、月壤和内部层圈结构的形成以及月球演化的历程;②探测月球的资源、能源和特殊环境的开发利用及对人类社会长期可持续发展的支撑。我国不载人月球探测划分为绕、落、回三个阶段。为了全球性、整体性重新认识月球,绕月卫星探测的科学目标是为了获取全月面三维影像,探测14种有用元素的全球分布与丰度,探测月壤厚度并估算氦 3资源量以及太阳活动对空间环境的影响。"落"为月球探测器软着陆就位探测和月球车巡视探测,建立月基光学、低频射电和极紫外天文观测平台。"回"为月球探测器软着陆就位探测和取样返回地面。     

试论月球科学与类地行星研究的学科属性

我国月球探测一期工程获国家批准立项和“嫦娥一号”卫星成功发射及运行这一历史性事件标志着我国已继人造地球卫星、载人航天阶段之后,开始进入人类航天活动的第三领域——深空探测。无疑此时探讨人类这一伟大社会实践活动的自然科学意义,特别是深空探测对象的科学内涵具有重要的现实意义。随着相关技术的开发、创新和成熟,工作重点将逐渐转移到深空探测对象本身的科学研究上来,即认识地球之外的行星体以及更深刻地重新审视地球。本文讨论了现阶段深空探测对象——月球及类地行星的基本物质属性,回顾美国和前苏联两国探月计划实施历史的启示,Apollo计划的演变．科学内容的纳入及宇航员地学素养的要求,Apollo登月计划的实施对月球科学本身的促进,以及对20世纪地球科学发展、人才队伍建设和分析技术进步等的重大影响,总结了前苏联探月计划的成败及其教训,并对我国月球探测工程立项历史等方面进行了分析。在此基础上,论述了月球科学及类地行星研究的地球科学属性,并强调指出地球科学家应将月球及整个类地行星研究纳入到地球系统科学的框架之中。     

Mechanical characteristics of a lunar regolith simulant at low confining pressure

Manned lunar exploration has recently attracted renewed interest. This includes the NASA Constellation program to return humans to the Moon by 2020, the ESA Aurora program which may use the Moon as a way station to prepare for major interplanetary exploration by 2025, and the PRC program to send a human to the Moon by 2030 and build a temporary manned lunar base by 2040. One of the problems demanding a solution is the stresses on the mechanical characteristics of the lunar regolith under the microgravity environment. The gravity on the Moon is about 1/6 that on Earth. The regolith is subject to very low confining stresses under a microgravity environment and the mechanical properties can change correspondingly. Because of the limited amount of lunar regolith brought back to Earth by the Apollo missions, a lunar regolith simulant was developed using silicon carbide to investigate the properties of the lunar regolith. Based on triaxial tests, this study analyzed the mechanical properties of the lunar regolith simulant at low stresses including the shear strength, peak strength and dilatation angle. The research results provide useful information on lunar regolith characteristics for astronauts returning to the Moon and for building a temporary manned lunar base.     

Frontiers in lunar science based on bibliometric analysisSCIEI北大核心CSCD

月球是人类开展深空探测的首选目标,月球探测是世界各国科技竞争的制高点。开展月球科学前沿研判,对我国实施深空探测战略、规划行星科学研究路径,进而赢得未来竞争优势至关重要。基于Web of Science数据库,本文利用文献计量学方法,对月球科学领域论文产出数量、学科和期刊分布、主要国家和领先机构的竞争力、国际合作等进行了深度分析,并通过聚类分析获得当前研究热点,梳理出五大研究领域和七大前沿问题。过去20年,我国在月球科学研究取得了长足进步,但仍然存在优秀论文少、顶尖学者少、学术期刊少的问题。未来月球科学可能在三个方向上实现突破:月球的水仍将是国际月球探测和研究的重点;月球内部结构探测或是我国弯道超车的机遇;新的月球样品将进一步揭示月球形成和演化的奥秘。本研究结果可以为我国未来月球探测和研究的规划与组织提供参考。     

Creation of a Global Selenocentric Coordinate Reference Frame

A number of questions about the Moon remain to be answered, including fundamental questions related to the internal structure and origin of the Moon. Studies of the spin–orbital dynamics of the Moon and of selenodesy are required for the practical solution of a number of problems related to navigation on the Moon and in circumlunar space, with the aim of providing coordinate and time support for planned lunar space projects. This paper analyzes existing dynamic selenographic reference grids, considers methods for their development and creation, and describes the modern projects related to navigational support for lunar missions. This paper is based on a presentation made at the conference “Modern Astrometry 2017,” dedicated to the memory of K.V. Kuimov (Sternberg Astronomical Institute, Moscow State University, October 23–25, 2017).

     

Advances in lunar science from the Clementine mission: A decadal perspective

The Clementine spacecraft orbited the Moon and acquired science data for 10 weeks in the Spring of 1994. During this time it collected global 11-band multispectral images and near global altimetry. Select areas of the Moon were imaged at 25 m/pixel in visible light and 60 m/pixel in thermal wavelengths. From these datasets a new paradigm for the evolution of the lunar crust emerged. The Moon is no longer viewed as a two-terrane planet, the Apollo samples were found not to represent the lunar crust as a whole, and the complexity of lunar crustal stratigraphy was further revealed. More than ten years later the Clementine datasets continue to significantly advance lunar science and will continue to do so as new measurements are returned from planned missions such as Chandrayaan, SELENE, and Lunar Reconnaissance Orbiter. This paper highlights the scientific research conducted over the last decade using Clementine data and summarizes the influence of Clementine on our understanding of the Moon.     

Luna-Glob project in the context of the past and present lunar exploration in Russia

The Russian Luna-Glob project has been conceived with a view to understand the origin of the Earth-Moon system. The objectives and main features of the Luna-Glob mission, which will mainly study the internal structure of the Moon by seismic instruments, are described in the context of the past and current program of lunar exploration in Russia.     

The Apollo missions and Moon rocks, 1969–1972

On 16 July 1969, three men set off for the Moon; just four days later, two of them planted their feet on its surface. Their objectives: to explore the lunar surface, carry out experiments, and gather geological samples for study. Geology was at the very centre of the Moon missions, and recovery of Moon rocks one of the measures of success. The samples obtained are amongst the most treasured natural artefacts of science.     

The Clementine mission —A 10-year perspective

Clementine was a technology demonstration mission jointly sponsored by the Department of Defense (DOD) and NASA that was launched on January 25th, 1994. Its principal objective was to use the Moon, a near-Earth asteroid, and the spacecraft’s Interstage Adapter as targets to demonstrate lightweight sensor performance and several innovative spacecraft systems and technologies. The design, development, and operation of the Clementine spacecraft and ground system was performed by the Naval Research Laboratory. For over two months Clementine mapped the Moon, producing the first multispectral global digital map of the Moon, the first global topographic map, and contributing several other important scientific discoveries, including the possibility of ice at the lunar South Pole. New experiments or schedule modifications were made with minimal constraints, maximizing science return, thus creating a new paradigm for mission operations. Clementine was the first mission known to conduct an in-flight autonomous operations experiment. After leaving the Moon, Clementine suffered an onboard failure that caused cancellation of the asteroid rendezvous. Despite this setback, NASA and the DOD applied the lessons learned from the Clementine mission to later missions. Clementine set the standard against which new small spacecraft missions are commonly measured. More than any other mission, Clementine has the most influence (scientifically, technically, and operationally) on the lunar missions being planned for the next decade.     

Japanese lunar robotics exploration by co-operation with lander and rover

Unmanned mobile robots for surface exploration of the Moon or planets have been extensively studied and developed. A lunar rover is expected to travel safely in a wide area and explore in detail. Japanese lunar robotics exploration is under study to conduct an unmanned geological survey in the vicinity of central peaks of impact craters for investigation of the sub-surface materials. This will give us the key information to study the lunar inner structure and understand the Moon’s origin and evolution as well as to investigate the evolution of magma ocean and later igneous processes. To carry out the geological exploration in the central peak, lander and rover co-operative exploration is proposed. The working group has been conducting feasibility study of advance technologies. This paper addresses an overview of lunar exploration with lander and rover and also enumerates future technologies to be established. The rover R&D group has developed an innovative science micro rover with a new mobility system and a lightweight manipulator. The design and implementation of a science rover for the near future lunar missions requiring long traverses and scientific observations are described and some experimental results are presented.