Observational astrochemistry: recent results, W M Irvine. Interstellar dust as the source of organic molecules in Comet Halley, J M Greenburg. On the origin of p/Halley dust component, L M Mukhin et al . Halley's polymeric organic molecules, W F Huebner et al . Complex organic ions in the atmosphere of Comet Halley, D L Mitchell et al . Organic solids produced from simple C/H/O/N ices by charged particles: applications to the outer solar system, B N Khare et al . Origin of organic compounds in carbonaceous chondrites, J R Cronin. Dark surfaces of asteroids and comets: evidence for macromolecular carbon compounds, D P Cruikshank. Prospects for the existence and detectability of an ocean on Europa, S W Squyres. Comets as a source of preformed material for prebiotic evolution, B C Clark. Microgravity particle research on the space station: the gas-grain simulation facility, G Fogleman, et al .