Transmission electron microscopy has been used to examine carbon isolated from the Allende meteorite. The structure of the carbon is rather disordered, consisting of curved and faceted graphene sheets with little large scale graphitization, and resembles that of a microporous carbon following high temperature heat treatment. Closed carbon nanoparticles, typically Ο2-10 nm in diameter are commonly observed. These closed particles, which are probably fullerene-like in structure, are strong candidates to be carriers of planetary gases. © 2000 Elsevier Science B.V. All rights reserved.