Origin and processing of water in the early Solar System

液态水使地球上的生命得以发展。然而，我们仍在思考一些基本问题，比如太阳系的水从何而来，以及水是什么时候被输送到太阳系内部的岩石行星上的？这些引人入胜的问题激发了我在行星和地球科学领域的跨学科研究。在地球上寻找答案可能会很困难，因为我们的星球表面自形成以来一直在不断地被侵蚀和再循环。然而，在太阳系周围呼啸而过的小行星，我们可以通过在地球上发现的陨石进入它们，它们保存了行星形成时期的重要记录。通过这个STFC欧内斯特卢瑟福奖学金，我的目标是描述这些行星构建块中的水库存，以限制太阳系中水的起源。最终，更好地了解我们太阳系中水的起源将有助于解释最近在太阳系外发现的含水的星子。太阳系的形成始于大约45.7亿年前一个密集分子云的坍缩。从那里开始，它经过了几个步骤，在太阳系内部形成了岩石行星：尘埃的凝结，厘米大小的颗粒的聚集，10-100公里大小的行星胚胎的吸积，其中一些物体的加热和融化，最后进一步的碰撞导致了更大行星的形成。今天火星和木星轨道之间的小行星带包含了这些行星胚胎的残余物，它们从未进入最后的行星阶段。这个小行星带是地球上发现的大多数陨石的来源。研究这些样本可以让我们了解太阳系诞生时发生的一些过程。不同类型的陨石形成于离太阳不同的距离，太阳形成后的时间也略有不同。有些直接来自环绕年轻太阳的物质盘（球粒陨石组），有些则是由更大的天体融化形成的（无球粒陨石组）。以前对早期太阳系水的研究主要集中在碳质球粒陨石群上，其中含有丰富的碳和水。然而，由于以前很少有研究集中在这些样本上，因此人们对更古老的陨石群（普通球粒陨石和早期形成的无球粒陨石）中的水的特征知之甚少。它们的水储量与碳质球粒陨石群的水储量一致吗？它和彗星相比如何？在早期太阳系中是否存在以前未被发现的未知水库？水的同位素特征是否随着离太阳的形成距离而变化？我将建立一个全面的清单，在太阳系形成后的500万年里，在未被探索的物体中形成水，并将这些新数据整合到早期太阳系的进化模型中。我的研究将为行星构造块中的水的起源及其在最终导致岩石行星形成的演变过程中的处理提供新的限制。这个与太空有关的话题是及时的，因为有几个即将到来的国际太空任务将访问原始小行星并收集材料返回地球。我将利用公众对太空探索的兴奋和兴趣，将其作为吸引人们参与科学的绝佳机会。为此，我将参加曼彻斯特大学同位素小组参加的众多外展活动，并通过其流行的“地球和太阳系”博客交流我的发现。

Liquid water allowed life to develop on the Earth. Yet we are still pondering on fundamental questions such as where does Solar System water come from, and when was it delivered to rocky planets in the inner Solar System? These fascinating issues motivate my interdisciplinary research across Planetary and Earth Sciences. Finding answers on the Earth may prove difficult because our planet's surface has been continuously eroded and recycled since its formation. However, asteroids whizzing around the Solar System, and to which we have access through meteorites found here on the Earth, have preserved vital records of the planet-forming epoch. Through this STFC Ernest Rutherford Fellowship I aim to characterise the water inventory in these planetary building blocks, in order to constrain the origin(s) of water in the Solar System. Eventually, a better understanding of the origin of water in our own Solar System will help interpretation of the recent discoveries of water-bearing planetesimals in extrasolar systems.The formation of our Solar System started some 4.57 billion years ago from the collapse of a dense molecular cloud. From there it took several steps to form rocky planets in the inner Solar System: condensation of dust, agglomeration of cm-sized grains, accretion of 10-100 km-sized planetary embryos, heating and melting of some of these objects, and eventually further collisions leading to the formation of larger planets. The asteroid belt present today between the orbits of Mars and Jupiter contains leftovers of these planetary embryos that never made it to the final planet stage. This asteroid belt is the source of most meteorites found on the Earth. Studying these samples provides us with access to some of the processes that took place during the birth of our Solar System. Different types of meteorites formed at different distances from the Sun, and at slightly different times after the Sun's formation. Some accreted directly from the disc of materials orbiting the young Sun (the chondrite group), and others formed through melting of larger bodies (the achondrite group). Previous studies on water in the early Solar System have focused on the carbonaceous chondrite meteorite group, which contains an abundance of carbon and water. However, the characteristics of water in older groups of meteorites (ordinary chondrites and early-formed achondrites) are poorly understood since very few studies have ever focused on these samples before. Is their water inventory consistent with that of the carbonaceous chondrite groups? How does it compare with comets? Were there previously unrecognised unknown water reservoirs that existed in the early Solar System? Does the isotopic signature of water vary with formation distance from the Sun? I will establish a comprehensive inventory of water in unexplored types of objects formed within 5 million years of the Solar System's formation, and integrate these new data into models of evolution of the early Solar System. My study will provide new constraints on the origin of water in planetary building blocks and its processing during their evolution that eventually led to the formation of rocky planets. This space-related topic is timely as there are several upcoming international space missions that will visit primitive asteroids and collect materials to return to the Earth. I will leverage the excitement and the public interest for space exploration as a fantastic opportunity for engaging people towards Science. To this end I will participate in the numerous outreach activities attended by the Isotope group at the University of Manchester, and communicate my discoveries through its popular 'Earth and Solar System' blog.