Reconstructing thermal and fluid alteration histories of planetary materials

在这个联盟中，来自英国三家机构的科学家们聚集在一起，探索我们太阳系内岩石体的发展，特别是与生命的关键成分，即水和富含碳的分子的存在和性质有关。我们工作的一个重点将是小行星，它们的样本已经作为陨石来到地球。这些天体在太阳系历史的早期就形成了，并且进化得很快，可能是由放射性化学元素衰变产生的内部热量驱动的。我们想知道这些小行星是在太阳系的什么地方形成的，它们成长需要多长时间，冷却的速度有多快。我们还想了解加热和冷却是如何影响水和富含碳的分子的，这些分子在小行星成长的过程中融入了它们。这些问题将通过同位素分析来确定不同类型矿物的年龄，以及用激光束技术研究富碳化合物结构的变化来回答。这项工作的结果将提供对小行星演化的新理解，可以用来帮助解释它们的样本，这些样本将很快被机器人任务送回地球。我们还将研究来自火星的陨石。这颗行星是小行星进化的中间阶段，小行星在数亿年前失去热量和液态水而“死亡”，而地球仍然是一个活跃的行星，拥有内部热量、液态水和复杂的富含碳的分子，包括生命。我们将分析的火星陨石形成于大约13亿年前，当时火星的温度仍然很高，以至于它的部分外表面可以融化，它们保留了流过岩石的液态水的痕迹。通过研究这些岩石中的矿物质和构成它们的化学元素，我们将探索熔融岩石冷却时晶体是如何生长的，也将确定水是何时存在的。今天的火星表面非常不适合生命生存，温度极端，很少或没有液态水，还有强烈的紫外线照射。然而，今天火星表面短暂出现的水，以及过去的温泉烧结矿床，可能包含生命的证据，但人们对它们存在的倾向知之甚少。由于将机器人地质学家送到火星是非常昂贵的，我们将通过研究智利山区的火星模拟地点来发现这些环境是否能孕育生命的分子迹象。这些地区的土壤非常干燥，它们的温度波动很大，而且它们沐浴在紫外线下。我们将尝试在这些土壤中寻找过去生命的痕迹，我们将通过在实验室中模拟火星条件来进一步探索分子保存。这些新信息将告诉我们，在未来的机器人和载人任务中，我们应该集中精力在火星上寻找生命的痕迹。这项研究的结果将免费提供给世界各地的其他科学家，以便改进行星演化的模型。这些新的数据和模型将有助于指导未来对小行星和火星的探索，包括未来几十年将样本送回地球的激动人心的任务。我们的研究也将引起研究地球历史、气候和生命的科学家的兴趣，并通过我们将开发的新的分析程序和技术对工业产生兴趣。由于我们的工作将探索新的和令人兴奋的科学主题，它将引起公众的极大兴趣，并将通过科学节、报纸和社交媒体进行交流。

In this consortium scientists from three UK institutions have come together to explore the development of rocky bodies within our solar system, and particularly in relation to the presence and properties of the key ingredients for life, namely water and carbon-rich molecules.One focus of our work will be on asteroids, samples of which have come to Earth as meteorites. These objects formed very early in the history of the solar system and evolved quickly, probably driven by internal heat from the decay of radioactive chemical elements. We want to know where in the solar system some of these asteroids formed, how long it took them to grow and how quickly they cooled down. We would also like to understand how heating and cooling affected water and carbon-rich molecules that became incorporated into the asteroids as they grew. These questions will be answered by using isotope analysis to determining the ages of different types of minerals, and by studying changes to the structure of carbon-rich compounds with laser beam techniques. Results from this work will provide new understandings of the evolution of asteroids that can be used to help interpret samples of them that will soon be returned to Earth by robotic missions.We will also study meteorites from Mars. This planet is an intermediate stage in evolution between the asteroids, which 'died' as they lost their heat and liquid water thousands of millions of years ago, and the Earth that remains an active planet with internal heat, liquid water and complex carbon-rich molecules including life. The Martian meteorites that we will analyse formed about 1300 million years ago when the planet was still hot enough that parts of its outer surface could melt, and they preserve traces of liquid water that flowed through the rocks. By studying the minerals in these rocks and the chemical elements from which they are made, we will explore how crystals grew as the molten rock cooled, and will also determine when the water was present. Today the surface of Mars is very hostile to life, with extremes of temperature, little or no liquid water and intense irradiation by ultraviolet light. However, brief occurrences of water on the surface of Mars today, and past hot-spring sinter deposits, may contain evidence of life, yet their propensity to do so is poorly understood. As sending robotic geologists to Mars is very costly, we will discover whether these environments can harbor molecular signs of life by studying martian analogue sites in the mountains of Chile. Soils in these areas are very dry, their temperatures fluctuate over a wide range and they are bathed in ultraviolet light. We will try to find traces of past life in these soils, and we will explore molecular preservation further by simulating martian conditions in the laboratory. This new information will tell us where on Mars we should focus the search for traces of life during future robotic and manned missions.The results of this research will be made freely available to other scientists worldwide so that improved models of planetary evolution can be developed. These new data and models will then help to guide the future exploration of asteroids and Mars, including the exciting missions in the next few tens of years that will return samples to Earth. Our research will also be of interest to scientists who study the history of the Earth, its climate and its life, and to industry through the new analytical procedures and technologies that we will develop. As our work will explore new and exciting science topics, it will be of great interest to the public and will be communicated via science festivals, newspapers and social media.