Noble Gases in Terrestrial Planets: Evidence for Cometary Impacts?
The possible role of comets in bringing volatiles to the inner planets is investigated by means of laboratory studies of the ability of ice to trap gases at low temperatures. The pattern of the heavy noble gases formed in the atmosphere of Venus can be explained by the impact of a planetesimal composed of ices formed in the range of 20 to 30 K. The noble gas patterns on Mars and Earth are less explicable by cometary bombardment alone.
KeywordsSolar Wind Enrichment Factor Terrestrial Planet Solar Nebula Lunar Soil
Unable to display preview. Download preview PDF.
- Donahue, T.M., and Pollack, J.B. (1983). ‘Origin and evolution of the atmosphere of Venus.’ In Venus, D.M. Hunten, L. Colin, T.M. Donahue, and V.I. Moroz (eds.), University of Arizona Press, Tucson, pp. 1003–1036.Google Scholar
- Hunten, D.M., Pepin, R.O., and Owen, T. (1988). ‘Planetary atmospheres.’ In Meteorites and the Early Solar System, J.F. Kerridge and M.S. Matthews (eds.), University of Arizona Press, Tucson, pp. 565–594.Google Scholar
- Wieler, R., Etique, Ph., Signer, P., and Poupean, G. (1983). ‘Decrease of the solar flare/solar wind flux ratio on the past several aeons deduced from solar neon and tracks in lunar soil plagioclases.’ J. Geophys. Res. 88 Supp., A713-A724.Google Scholar