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

行星形成时的环境是怎样的？影响它们形成的主要因素是什么？太阳系是由什么构成的？类似的过程有多大可能在其他恒星周围形成像地球和火星这样的行星？通过研究我们自己的行星系统的起源，我们可以了解到银河系其他地方可能存在的类地行星吗？这些是我们希望在提议的研究中帮助回答的一些问题。人们认为太阳系是由星云形成的，星云是由尘埃和气体云组成的。这些物质的组成尚不清楚，但我们确实知道，星云的一部分在引力作用下坍塌，在年轻的太阳周围形成了一个圆盘（所谓的原行星盘），并在各种不同的环境中经历了一系列温度的处理，然后聚集在一起形成了行星。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蚀和含水蚀变。因此，它提供了一个独特的窗口，在磁盘条件之前的吸积的第一个固体。我们对早期太阳系热环境的认识来自于对这些稀有陨石的化学和矿物学分析。但这些模型很大程度上是基于大型（几克）大块异质陨石的化学成分，这些成分是在非常不同的环境中形成的。近年来，我们的团队一直站在扩展宇宙化学边界的最前沿，使用新的工具来解开早期太阳系的过程。我们已经开发出一种独特的方法，使我们能够确定太阳系内部最早形成的一些固体的化学成分。我们已经证明了我们技术的有效性，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，现在我们第一次能够在这些高度异构的对象中定义单个组件的组合构成。了解球粒成分的化学性质使我们能够定义我们自己的原行星盘的热环境——它的异质性，以及挥发性耗竭（我们到达岩石内行星的机制，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，了解其他恒星周围的盘和行星是如何形成的。我们的提议是为一名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之外。该研究与STFC交付计划2008/9-2011/12中概述的“行星系统如何进化”和“化学元素是如何产生的”主题特别相关。

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 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 and planets around other stars may have formed. 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.