权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Planetary Origins and Development

行星起源与发展

基本信息

批准号：
ST/G00272X/1
负责人：
Alex Halliday
金额：
$ 212.31万
依托单位：
University of Oxford
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FG00272X%2F1
关键词：
Planetary Origins Development

项目摘要

The research in this proposal tries to answer a string of questions about why we are here. Not just why you and I are here. Not even why life started. But why we have a Solar System, at all. We are sure the planets formed from a swirling disk of gas and dust. However, we do not know much about how the planets formed, and how material in the disk was redistributed. We can get clues from precise measurements of small differences in the kinds of atoms present. This isotopic heterogeneity came from stars that predated our sun. These act as a signature of the dust characterising different parts of the disk allowing us to track motions rather like a detective uses fingerprints to trace a criminal. We have tentative evidence that Mars, a small planet, actually formed very fast, at the same time as Jupiter should have been forming a bit further away. Maybe Jupiter accumulated most of the dust and debris and did not leave much for Mars to get bigger. The first thing to do is to check out this evidence on timing and see if it is right. We need to improve the trace element and isotopic measurements to achieve this. We think the Moon formed from the debris left from a collision between Earth and another planet. The debris was so hot that it vaporised and some was lost to space. We have evidence that alkali metals like rubidium were also lost. We need to check out this theory with more measurements and see what else evaporated when planets were made. We also think metal cores form from an ocean of molten rock created from the incredible heat resulting from collisions with other planets and impactors. We can figure out the temperatures and pressures and composition of the planet at the time by measuring trace elements and comparing their concentration with what you predict from experiments. We want to know how melting works on planets that have lots of volcanism. We will model the behaviour of one of Jupiter's moons (called Io) and make comparisons with the early Earth which is a time when tidal effects would have produced extensive melting. We need to establish how volcanism generates atmospheres. The depletion in volatile elements in the terrestrial planets provide clues but they are not well understood. We will develop new models to try and constrain this. We will also study how volcanism affects planetary environments and their habitability. In particular, we will investigate how lightning is generated in volcanic planetary environments. Lastly, we will look at the issue of why the basic building blocks of life on Earth have a certain 'left handed' molecular structure. We think this chirality may have something to do with the way amino acids interacted with clays in the early Earth and will conduct experiments aimed at evaluating this.

这项提案中的研究试图回答一系列关于我们为什么会在这里的问题。不仅仅是你和我在这里的原因。甚至不知道生命为什么开始。而是为什么我们有一个太阳系。我们确信这些行星是由气体和尘埃组成的漩涡盘形成的。然而，我们对行星是如何形成的，以及盘中的物质是如何重新分布的知之甚少。我们可以从对存在的原子种类的微小差异的精确测量中获得线索。这种同位素的不均一性来自太阳之前的恒星。这些作为尘埃的签名，表征了磁盘的不同部分，使我们能够跟踪运动，就像侦探使用指纹追踪罪犯一样。我们有初步证据表明，火星这颗小行星实际上形成得非常快，与木星同时形成的应该是更远的地方。也许木星积累了大部分的尘埃和碎片，没有留下太多让火星变大的东西。首先要做的是检查这个时机的证据，看看它是不是正确的。我们需要改进痕量元素和同位素测量来实现这一点。我们认为月球是由地球与另一颗行星碰撞后留下的碎片形成的。碎片是如此之热，以至于它蒸发了，一些碎片丢失到太空中。我们有证据表明，像Rb这样的碱金属也丢失了。我们需要用更多的测量来检验这一理论，看看当行星形成时还蒸发了什么。我们还认为，金属核心是由熔岩海洋形成的，熔岩是由与其他行星和撞击器碰撞产生的令人难以置信的热量形成的。我们可以通过测量微量元素并将它们的浓度与你从实验中预测的浓度进行比较，来计算出当时地球的温度、压力和组成。我们想知道在火山活动频繁的行星上融化是如何起作用的。我们将模拟木星的一颗卫星(称为木卫一)的行为，并与早期地球进行比较，当时潮汐效应会导致大范围融化。我们需要确定火山是如何产生大气的。类地行星中挥发性元素的枯竭提供了线索，但人们对这些线索还不太清楚。我们将开发新的模式来尝试和限制这一点。我们还将研究火山作用如何影响行星环境及其宜居性。特别是，我们将调查闪电是如何在火山行星环境中产生的。最后，我们将探讨为什么地球上生命的基本构件具有某种“左撇子”分子结构。我们认为这种手性可能与早期地球上氨基酸与粘土相互作用的方式有关，并将进行旨在评估这一点的实验。