"What happened to the Apollo original filming on the moon? Where are they for public view? not the broadcast or polaroid taken from the monitor"
-
Habitable Planets: Oxygen and Climate (2)
PI: James Kasting
The proposed work involves theoretical modeling of the composition and climate of early atmospheres on Earth and Mars and of planets near the outer edge of a star’s habitable zone. Two specific tasks are outlined: 1) A 1-D photochemical model will be used to investigate the possibility that sulfur isotopes were mass-independently fractionated during photolysis of SO2 in Earth’s early atmosphere. The model will incorporate new theoretical insights into SO2 self-shielding developed by James Lyons of UCLA. A time-dependent model that simulates volcanic injection of SO2 into the early stratosphere will be developed for this study. This model is expected to yield new insights concerning the concentration of O2 in the Archean atmosphere and the anomalous pattern of sulfur isotopes in rocks dated between 2.8 and 3.2 Ga. 2) A 3-D general circulation model (GCM) will be used to simulate the climate of a CO2-rich early Mars. The model will incorporate new correlated-k absorption coefficients for CO2-H2O mixtures supplied by Eli Mlawer of Cambridge Atmospheric and Environmental Research. The model will be used to determine whether a warm, Earth-like climate could have existed on Mars prior to 3.8 Ga when most of the fluvial valleys appear to have formed. This same model will be used to evaluate the effect of CO2 clouds on the location of the outer edge of the liquid water habitable zone around the Sun and other main sequence stars. This work has relevance both to future Mars missions and to NASA’s proposed Terrestrial Planet Finder missions.
May 16, 2012
