Reconstructing thermal and fluid alteration histories of planetary materials

在这个联盟中，来自英国三个机构的科学家聚集在一起，探索我们太阳系内岩石天体的发展，特别是与生命的关键成分，即水和富碳分子的存在和性质有关的问题。我们的工作重点之一将是小行星，它们的样本已经以陨石的形式来到地球。这些天体在太阳系的历史上形成得非常早，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。我们想知道其中一些小行星是在太阳系的什么地方形成的，它们需要多长时间才能生长，它们冷却的速度有多快。我们还想了解加热和冷却是如何影响水和富碳分子的，这些分子在小行星生长过程中被并入其中。这些问题将通过使用同位素分析来确定不同类型矿物的年龄，并通过激光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，可以用来帮助解释即将由机器人任务返回地球的小行星样本。我们还将研究来自火星的陨石。这颗行星是小行星和地球之间进化的中间阶段。小行星在几百万年前失去了热量和液态水，而地球仍然是一个活跃的行星，拥有内部热量、液态水和包括生命在内的复杂的富碳分子。我们将分析的火星陨石形成于大约1.3亿年前，当时火星仍然足够热，其外表面的部分可以融化，它们保留了流经岩石的液态水的痕迹。通过研究这些岩石中的矿物和构成它们的化学元素，我们将探索熔岩冷却时晶体是如何生长的，并将确定水的存在时间。今天，火星表面非常不利于生命，极端的温度，很少或根本没有液态水，以及紫外线的强烈照射。然而，今天火星表面短暂出现的水，以及过去的温泉烧结矿沉积，可能包含生命的证据，但人们对它们这样做的倾向知之甚少。由于向火星派遣机器人地质学家的成本非常高，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可以蕴藏生命的分子迹象。这些地区的土壤非常干燥，温度波动范围很大，而且沐浴在紫外线下。我们将努力在这些土壤中寻找过去生命的痕迹，并将通过在实验室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，我们应该把重点放在火星上的哪里寻找生命的痕迹。这项研究的结果将免费提供给世界各地的其他科学家，以便开发改进的行星进化模型。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，包括未来几十年将把样品送回地球的令人兴奋的任务。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分析程序和技术吸引工业界。由于我们的工作将探索新的和令人兴奋的科学主题，公众将非常感兴趣，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.