title: Comets as porous aggregates of interstellar dust.
abstract: A comet model is derived based on the interstellar dust chemical composition in dense molecular and diffuse clouds resulting from their subsequent chemical interactions and UV photoprocessing. The collapsing presolar nebula leads to a porous aggregate model for comet nuclei, from which is derived certain physical properties that include thermal conductivity and tensile strength. The porous morphological structure is also shown to imply anomalous (expansion rather than contraction) behavior when subjected to strong shock waves, which is supported by recent shock experiments on (porous) carbonaceous chondrite material.
authors.affiliation: Department of Astrophysics, Leiden University, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Greenberg
authors.forename: J L
authors.initials: JL
authors.lastname: Remo
mesh_terms: D019443:Cosmic Dust; D018559:Exobiology; D005118:Extraterrestrial Environment; D019110:Meteoroids; D008962:Models, Theoretical; D009930:Organic Chemicals / Q000032:analysis
chemical_list: D019443:Cosmic Dust; D009930:Organic Chemicals