Unravelling the secrets of early Solar System processes through laboratory investigations of regolith from a C type asteroid

研究地外样品的最大挑战之一是，大部分地质背景都缺失了，而在地球上，我们甚至可以在收集样品和随后的实验室分析之前获得有关位置，方向，周围岩石等的现场信息。正在进行的太空任务（OSIRIS-Rex和Hayabusa 2）到原始C型小行星（可能是碳质球粒陨石的母体）计划在21世纪20年代初将克的物质返回到公斤。他们将从一个特定的小行星上收集样本，但他们收集的样本将从混合良好的表面风化层中获取，其本质上几乎不包含地质背景。碳质陨石被认为是来自C型小行星，其中一些显然是锂化的风化岩和角砾岩（如图1）。因此，它们提供了一个独特的机会，可以通过详细的矿物学、化学和同位素调查，了解从混合风化层中可以确定哪些关于母小行星的信息。地球附近的原始小行星通常是碎石堆，因此风化层预计由母体中存在的所有主要岩性组成，包括碎屑间区域中最原始的物质，因为它们太脆弱，无法作为大型碎屑生存。因此，该项目的一部分将是调查外来岩性和成分的碎屑间物质的性质

One of the biggest challenges with the study of extra-terrestrial samples is that much of the geological context is missing, whereas on Earth we can have access to field information about location, orientation, surrounding rocks, etc before even collecting a sample and subsequent laboratory analyses. On-going space missions (OSIRIS-Rex and Hayabusa2) to primitive C-type asteroids (likely parent bodies for carbonaceous chondrite meteorites) are scheduled to return grams to kgs of material in the early 2020s. They will collect samples from a specific asteroid, but the samples they collect will be grabbed from the well-mixed surface regolith, which by its very nature contains little geological context. The carbonaceous chondrites are believed to originate from C-type asteroids, some of which are clearly lithified regoliths and breccias (e.g. Fig 1). As such they offer a unique opportunity to understand what can be determined about the parent asteroid from a mixed regolith from detailed mineralogical, chemical and isotopic investigation. Primitive asteroids near Earth are usually rubble piles, and therefore the regolith is expected to be comprised of all the main lithologies present in the parent body, including the most primitive materials in the inter-clast regions as they are too friable to survive as large clasts. Therefore, part of the project will be to investigate the nature of the inter-clast materials for exotic lithologies and components