Organic matter
Organic matter in meteorites is carbon-based chemistry, made without life, that ranges from simple molecules to large, tar-like solids.
In chemistry, "organic" simply means compounds built around carbon, usually bonded to hydrogen, and it does not imply anything was ever alive. Carbonaceous chondrites can contain a few per cent carbon by weight, much of it as organic matter. Most is insoluble organic matter, a complex, cross-linked solid somewhat like coal or kerogen. A smaller soluble fraction includes amino acids, carboxylic acids, aromatic hydrocarbons and nucleobases.
These compounds matter because they show that the ingredients of biochemistry formed naturally in space and in water-rich asteroids, and that meteorites and dust could have delivered them to the early Earth. Their isotopes, often enriched in deuterium (heavy hydrogen) and nitrogen-15, point to formation in very cold environments such as the interstellar medium or the outer solar nebula.
Murchison (fell 1969, Australia) and Tagish Lake (fell 2000, Canada) are two of the most studied examples, and samples returned from asteroids Ryugu and Bennu have been analysed for comparison. You cannot see organic molecules, though they contribute to the black colour of CI and CM chondrites. Because human skin is covered in organic compounds, scientists handle such meteorites with clean gloves and tools.
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