The problem of precise characterization, analysis, and eventual identification of unknown materials arises in many fields and takes many forms, depending on the nature of the substances under study. In the first part of this paper we review common, modern mass spectrometry techniques applied to such studies. We also give an overview of improvements made to these technologies in recent years by Silicon Valley companies and other teams focused on precise biomedical research dependent upon sensitive techniques, yet applicable to a wide range of non-biological materials. In the second and third parts of the paper we review practical experiences applying these techniques to the simplest case of the characterization of solid materials (as opposed to liquids or gases) and comparing our results with previously undertaken isotopic analysis. In particular, we describe our correlations of that analysis with the patterns described by witnesses in a well-documented, still-unexplained incident, initially thought to be of aerospace origin, which gave rise to the deposition of unknown material, and by the investigators who handled it in the field and the laboratory. The lessons from this specific investigation are applicable to a wider range of issues in reverse engineering of complex, esoteric materials, and aerospace forensics.

未知材料的精确表征、分析和最终识别问题出现在许多领域，并有多种形式，具体取决于所研究物质的性质。在本文的第一部分，我们回顾了应用于此类研究的常见现代质谱技术。我们还概述了近年来硅谷公司和其他团队对这些技术所做的改进，这些团队专注于依赖敏感技术的精确生物医学研究，但适用于广泛的非生物材料。在本文的第二和第三部分，我们回顾了将这些技术应用于表征固体材料（与液体或气体相反）的最简单案例的实践经验，并将我们的结果与之前进行的同位素分析进行​​比较。特别是，我们描述了我们的分析与目击者描述的模式之间的相关性现场和实验室。这项具体调查的经验教训适用于复杂、深奥材料的逆向工程和航空航天取证中的更广泛问题。