The origin and evolution of the terrestrial planets

我们今天看到的太阳系，由一颗由行星环绕的中心恒星组成，它是由45亿年前坍缩的尘埃和气体云形成的。我们可以通过研究陨石来了解太阳系历史的早期阶段——岩石小行星（可能还有彗星）的样本，它们的内容为我们提供了它们所经历的事件的快照。一些小行星在它们的历史中一直处于休眠状态，并保留了曾经围绕新形成的太阳旋转的物质。通过分析这些小行星的原始陨石样本，我们计划研究它们包含的古老颗粒，以便更多地了解行星形成之前的太阳系环境。其他小行星要活跃得多，经历了加热、融化，甚至火成岩和火山活动。这些天体中存在的任何冰都已经融化，使液态水与岩石物质发生反应，产生含水矿物。通过研究这些经过处理的陨石中的矿物质，我们的目标是更多地了解早期太阳系中水的丰度和分布。除了水，许多小行星和彗星也含有有机物。正如我们所知，这两种成分是生命的关键成分。有人认为，地球形成后，生命发展所必需的水和有机物质实际上是由小行星和彗星的撞击带来的。因此，我们还将研究这些物质在撞击过程中的转移，方法是在实验室中使用各种靶和空心体模拟这一过程。水的存在和作用并不局限于地球、小行星和彗星。火星探测任务显示，火星表面散布着含水矿物，但尚未带回可供我们在实验室研究的样本。幸运的是，我们收集了一些来自火星的陨石，我们计划研究这些陨石，以了解水的作用和这个星球的可居住性。

The Solar System we see today, comprised of a central star orbited by planets, formed from a cloud of dust and gas that collapsed over 4.5 billion years ago. We can learn about the early stages of the Solar System's history by studying meteorites - samples of rocky asteroids (and possibly comets) whose contents provide us with snapshots of the events they have experienced. Some asteroids have remained rather dormant throughout their history, and preserve the very materials that were once swirling around the newly forming Sun. By analysing the primitive meteorites that sample such asteroids, we plan to study the ancient grains they contain in order to find out more about the solar system environment prior to planet formation. Other asteroids have been much more active, experiencing heating, melting and even igneous and volcanic activity. Any ices present in these bodies have melted, allowing liquid water to react with the rocky materials and produce water-bearing minerals. By studying the minerals in these processed meteorites we aim to learn more about the abundance and distribution of water in the early Solar System.As well as water, many asteroids and comets also contain organics. These two components are key ingredients to life as we know it. It has been suggested that once the Earth was formed, the water and organic material necessary for the development of life were actually delivered by impacting asteroids and comets. We will therefore also study the transfer of these materials during impacts by mimicking the process in the laboratory using various targets and bolides.The presence and action of water is not limited to the Earth, asteroids and comets. Missions to Mars have revealed its surface to be strewn with water-bearing minerals but have yet to return samples that we can study in the laboratory. We are fortunate to have a selection of meteorites that originated on Mars in our collection, and we plan to study these to learn about the action of water and the habitability of this planet.