title: Trapping of gases by water ice and implications for icy bodies.
abstract: The trapping of various gases by water ice at low temperatures (20-80K) and their release from the ice upon warming, was studied experimentally.  The results of these experiments, together with a computation of the thermal evolution of a cometary nucleus, can explain the gas and dust jets which were observed to emanate from the nucleus of P/Halley.  The experimental results are important also to the gas content of Titan.
authors.affiliation: Department of Geophysics and Planetary Sciences, Tel Aviv University, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Bar-Nun
authors.forename: D
authors.initials: D
authors.lastname: Prialnik
authors.forename: D
authors.initials: D
authors.lastname: Laufer
authors.forename: E
authors.initials: E
authors.lastname: Kochavi
mesh_terms: D000114:Acetylene; D001128:Argon; D002245:Carbon Dioxide; D002248:Carbon Monoxide; D005118:Extraterrestrial Environment; D005740:Gases; D006856:Hydrogen Cyanide; D007053:Ice; D019110:Meteoroids; D008697:Methane; D009584:Nitrogen; D018539:Saturn; D013696:Temperature; D014867:Water
chemical_list: D005740:Gases; D007053:Ice; D014867:Water; D002245:Carbon Dioxide; D006856:Hydrogen Cyanide; D001128:Argon; D002248:Carbon Monoxide; D009584:Nitrogen; D000114:Acetylene; D008697:Methane