The formation and evolution of the Solar System

早期太阳系形成的环境可以用那时的陨石来研究。这是一项旨在更多地了解行星是如何从尘埃和气体盘中形成的建议。我们提出了五个具体项目：项目A。被称为球粒的圆形球体在许多陨石中很常见。它们是在太阳系早期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，以确定球粒的相对年龄的精度是不可能的。我们想验证一个假设，即它们所经历的加热是行星吸积的必要步骤，也许触发了吸积过程。这是因为球粒的物理和同位素特性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。对太阳系中水的研究是了解行星体演化的基础。很明显，矿物质与水相互作用产生了水合物质。问题是这种水合作用是在哪里发生的--主要是在矿物的母体中，还是在太阳星云和母体的结合体中？这对确定早期太阳系中H2O的组成和位置很重要。 C项目如科学技术委员会网站所述，联合王国宇宙化学分析网络是一项综合计划，旨在开发新的分析技术，对地外物质进行实验室分析，特别是对从空间飞行任务直接返回地球的尘埃样品进行分析。UK-CAN的应用范围从恒星核合成物理学到生命起源，是天基行星飞行任务和地基观测天文学若干领域的重要补充。开发新仪器的必要性是由空间飞行任务所获得的样品即将返回以及地球外样品的性质所驱动的。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不等（有机物和纳米金刚石）。目前的技术只能对最大的同位素进行单独分析，而且分析仅限于主要的同位素。2004年从GENESIS、2006年从STARDUST和2007年从MUSES-C返回的样品以及可能从火星返回的土壤，都刺激了国际社会为样品分析的新时代做好准备。国家历史博物馆、开放大学和曼彻斯特大学是联合王国在实验室分析地外样品方面拥有主要专门知识和卓越记录的机构，这些机构构成了联合王国-国家样本网络的核心。D项目构成地外物质的矿物的化学性质有助于更好地了解太阳系中行星形成的环境。原位分析元素成分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中的硫化物结核，以努力了解行星形成前太阳系的热环境，并将使用同一套数据来探索行星和微行星核心结晶化的物理过程。E项目陨石通常含有未被很好研究的细粒基质，因为其亚微米粒度阻止了大多数分析技术。我们建议进行探路者实验，逐粒分析基质。目的是确定这些谷物的起源及其物理和化学历史。然后，我们将把它们与它们的类似物进行比较：年轻恒星周围的星周尘埃。

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.