The formation and evolution of the Solar System

早期太阳系形成的环境可以用那个时候的陨石来研究。这项提议是为了更多地了解行星是如何由尘埃和气体组成的圆盘形成的。我们提出了五个具体的项目：项目A。被称为球粒的圆形球体在许多陨石中很常见。它们是在早期太阳系的一次闪热事件中形成的。使用新开发的、高精度的镁同位素技术，我们建议以一种以前不可能达到的精度来确定球粒陨石的相对年龄。我们想要检验一个假设，即它们所经历的加热是行星吸积过程中的必要步骤，可能触发了吸积过程。这是因为球粒陨石的物理和同位素性质表明，它们是在高尘埃压力下形成的，这可能使吸积不可避免。项目B研究太阳系中的水是理解行星体演化的基础。很明显，矿物质与水相互作用，产生水合物质。问题是这种水合作用发生在哪里--主要是在矿物的母体中，还是在太阳星云和母体的组合中？这对于确定太阳系早期可利用的H2O的组成和位置是很重要的。项目C。如科学、技术和创新中心网站所述，英国宇宙化学分析网络是一个综合计划，旨在开发新的分析技术，用于对地外物质，特别是从空间飞行任务直接返回地球的尘埃样本进行实验室分析。应用范围从恒星核合成物理学到生命起源，英国-CAN是对天基行星飞行任务和地面观测天文学几个领域的重要补充。由于空间飞行任务获得的样本即将返回，以及地外样本的性质，因此需要开发新的仪器。从原始陨石中分离出来的星际颗粒大小从几微米到几纳米(有机物和纳米钻石)不等。按照目前的技术，只有最大的同位素可以单独进行分析，而且分析仅限于主要同位素。由于2004年《创世》、2006年《星尘》和2007年《缪斯-C》的样品回归，以及火星土壤的潜在回归，国际社会正准备进入样品分析的新纪元。国家历史博物馆、开放大学和曼彻斯特大学是英国在实验室分析地外样本方面拥有主要专业知识和卓越记录的机构，这些机构构成了英国-CAN的核心。项目D组成地外物质的矿物的化学有助于更好地了解太阳系中行星形成的环境。通过现场分析元素组成，可以进一步了解影响岩石的物理过程。在项目D中，申请者将研究铁陨石的硫化物结核，以努力了解行星形成前太阳系的热环境，并将使用相同的数据集来探索行星和行星体核心结晶所涉及的物理过程。项目E陨石通常含有一种尚未得到很好研究的细粒基质，因为其亚微米级的颗粒尺寸使大多数分析技术无法使用。我们建议进行探路器实验，以逐粒分析基质。目的将是确定这些谷物的来源，以及它们的物理和化学史。然后，我们将把它们与它们的类似物进行比较：年轻恒星物体周围的星际尘埃。

The environment in which the early solar system formed can be studied using meteorites that date from that time. This is a proposal to learn more about how the planets formed from a disk of dust and gas. We propose five specific projects:Project A. Rounded spheres called chondrules are common in many meteorites. They formed during a flash heating event in the early solar system. Using newly developed, highly precise, Mg isotope techniques, we propose to determine the relative age of chondrules to a precision not possible before. We want to test a hypothesis that the heating they experienced was a necessary step in planetary accretion, perhaps triggering the accretion process. This has been suggested because the physical and isotopic properties of chondrules suggest they formed at high dust pressures that may have made accretion inevitable. Project B. The study of water in the solar system is fundamental to understanding the evolution of planetary bodies. It is clear the minerals interacted with water to produce hydrated materials. The question is where did that hydration take place - primarily in the parent body of the minerals or in a combination of the solar nebula and parent body? This is important to determining the compositions and locations of reservoirs of H2O available in the early solar system. Project C. As stated on the STFC website, the UK Cosmochemistry Analytical Network is an integrated scheme for the development of new analytical technologies for the laboratory analysis of extraterrestrial material, particularly dust samples returned directly to Earth from space missions. With applications ranging from the physics of stellar nucleosynthesis to the origins of life, the UK-CAN is an essential complement to space-based planetary missions and to several areas of ground based observational astronomy. The need to develop new instrumentation is driven by the imminent return of samples obtained by space missions, as well as by the nature of extraterrestrial samples. Interstellar grains isolated from primitive meteorites range in size from a few microns to a few nanometres (organics and nanodiamonds). Only the largest can be analysed individually with present technology and analyses are limited to the major isotopes. The international community is gearing up towards a new era of sample analysis, stimulated by the return of samples from GENESIS in 2004, STARDUST in 2006 and MUSES-C in 2007, and the potential return of soil from Mars. The UK institutions with major expertise and a proven track record of excellence in the laboratory analysis of extraterrestrial samples are the National History Museum, the Open University and the University of Manchester and these institutions form the core of UK-CAN. Project D. The chemistry of the minerals that make up extraterrestrial materials lead to a better understanding of the environment in which the planets formed in the solar system. Analysing element composition in situ allows further understanding of the physical processes that affected the rocks. In Project D, the applicant will study sulphide nodules from iron meteorites in an effort to understand the thermal environment of the solar system prior to planet formation and will use the same data set to explore the physical process involved in the crystallisation of cores of planets and planetesimals. Project E. Meteorites often contain a fine grained matrix that has not been well studied, because its sub-micron grain size prohibits most analytical techniques. We propose to undertake pathfinder experiments to analyse matrix grain by grain. The aim will be to determine the origin of these grains, and their physical and chemical history. We will then compare them to their analogues: circumstellar dust around young stellar objects.