Defining the thermal environment of the proto-planetary circumsolar disk: Continuation

定义原行星环日盘的热环境：续

• 批准号: ST/G002967/1
• 负责人: Nicholas Rogers
• 金额: $ 5.14万
• 依托单位: The Open University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FG002967%2F1
• 关键词: Defining; thermal; environment; proto; planetary

What were conditions like when the planets were being formed, and what were the major factors that affected their formation? What was the solar system made from? How likely is it that similar processes acted to form planets such as the Earth and Mars around other stars? What can we learn about the possible existence of terrestrial-type planets elsewhere in the galaxy from studying the origins of our own planetary system? These are a few of the questions that we hope to help answer in the proposed research. It is thought that the solar system was formed from a nebula - a cloud of dust and gas. The composition of that material is not known, but we do know that a section of the nebula collapsed under gravity, formed a disk around the young sun (a so-called proto-planetary disk), and underwent processing at a range of temperatures, in a wide variety of environments, before clumping together to make planets. We're lucky in having a collection of samples that date from this earliest period in solar system history. Primitive meteorites are amongst our only samples of the proto-planetary nebula. In the most primitive meteorites, the mineralogy and chemistry of this material suggests that it escaped subsequent thermal and aqueous alteration within the asteroid. As such, it offers a unique window on conditions in the disk prior to accretion of the first solids. Our knowledge of the thermal environment of the early solar system comes from chemical and mineralogical analyses of these rare meteorites. But those models are largely based on the chemistry of large (a few grams) of bulk heterogeneous meteorites, where components formed in very different environments are measured together. Over recent years, our group has been at the forefront of extending the boundaries of cosmochemistry, using new tools to unravel early solar system processes. We have developed a unique methodology that allows us to determine the trace and minor element chemistry of some of the earliest solids formed in the inner solar system. We have proven the effectiveness of our technique, and our preliminary data already challenge existing models. We are world leaders in this type of work, and are now able to define the compositional makeup for individual components within these highly heterogeneous objects, for the first time. Knowing the chemistry of chondritic components allows us to define the thermal environment of our own proto-planetary disk - its heterogeniety, as well as processes such as volatile depletion (the mechanism by which we arrived at rocky inner planets, as opposed to objects like Uranus), and chondrule formation (the mechanism by which some of the first solids were formed). Understanding the chemistry and thermal environment of our own proto-planetary disk is vital in understanding its formation and evolution, and more generally, how disks around other stars form. Our proposal is for two years funding for a postdoctoral research scientist - an individual who is already a specialist in the relevant techniques - in addition to funding to cover instrumentation costs and consumables. The research is specifically relevant to the theme of 'How do planetary systems evolve', and 'How were the chemical elements created', outlined in the STFC Delivery Plan 2008/9-2011/12.

行星形成的条件是什么，影响它们形成的主要因素是什么？太阳系是由什么组成的？类似的过程在其他恒星周围形成地球和火星等行星的可能性有多大？从研究我们自己的行星系统的起源中，我们能了解到银河系其他地方可能存在的陆地型行星吗？这些是我们希望在拟议的研究中帮助回答的一些问题。人们认为太阳系是由一个星云--一个尘埃和气体云--形成的。该物质的成分尚不清楚，但我们知道星云的一部分在重力作用下坍塌，在年轻的太阳周围形成了一个圆盘（所谓的原行星盘），并在各种温度下进行加工，在各种环境中，然后聚集在一起形成行星。我们很幸运能收集到太阳系历史上最早时期的样本。原始陨石是我们仅有的原行星状星云样本之一。在最原始的陨石中，这种物质的矿物学和化学性质表明，它逃脱了小行星内部随后的热和水蚀变。因此，它提供了一个独特的窗口，在磁盘的条件之前，吸积的第一个固体。我们对早期太阳系热环境的了解来自于对这些稀有陨石的化学和矿物学分析。但这些模型在很大程度上是基于大的（几克）大块异质陨石的化学成分，其中在非常不同的环境中形成的成分被一起测量。近年来，我们的团队一直处于扩展宇宙化学边界的最前沿，使用新工具来解开早期太阳系的过程。我们开发了一种独特的方法，使我们能够确定内太阳系中形成的一些最早的固体的痕量和微量元素化学。我们已经证明了我们的技术的有效性，我们的初步数据已经挑战了现有的模型。我们是这类工作的世界领导者，现在能够首次定义这些高度异构对象中各个组件的组成。了解了行星成分的化学性质，我们就可以确定我们自己的原行星盘的热环境--它的不均匀性，以及挥发性耗尽（我们到达岩石内部行星的机制，而不是像天王星这样的物体）和球粒形成（一些第一批固体形成的机制）等过程。了解我们自己的原行星盘的化学和热环境对于理解它的形成和演化至关重要，更一般地说，其他恒星周围的盘是如何形成的。我们的建议是为博士后研究科学家提供两年的资金-一个已经是相关技术专家的人-除了支付仪器费用和消耗品的资金。该研究特别与2008/9-2011/12年STFC交付计划中概述的“行星系统如何演变”和“化学元素如何产生”的主题有关。