Please join us for a seminar sponsored by the Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics. Complete schedule at http://www.cfa.harvard.edu/amp/events.html 2:00 PM Tuesday, January 22, 2013 Phillips Auditorium 60 Garden St, Cambridge, MA Title: Production and escape of hot H_2 and OH molecules from upper planetary atmospheres Authors: M. Gacesa ( 1(current address), 2 ) and V. Kharchenko ( 2, 3 ) 1 Max Planck Institute for the Physics of Complex Systems, Dresden, Germany 2 ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 3 University of Connecticut, Storrs, CT Abstract Photodissociation of CO_2 and O_2 molecules followed by dissociative recombination of oxygen molecular ions are among the most important sources of hot oxygen atoms in the upper atmospheres of terrestrial planets. The hot oxygen atoms can transfer kinetic energy in collisions with thermal atmospheric gases, perturbing local thermal equilibrium conditions, inducing chemical reactions, and forming rotationally and vibrationally excited products. A specific process of interest in the upper atmospheres of Mars, Earth, and Venus is the reactive collision of hot O atom with a hydrogen molecule, leading to production of rotationally-vibrationally excited H_2 and OH molecules. We present new results of extensive reactive quantum scattering calculations of this process and their implications on the escape of H_2 , HD, and OH molecules from terrestrial planets. Specifically, we calculated molecular escape fluxes for Mars using a simple kinematic model for typical solar conditions. Our results indicate that direct collisional escape of light molecules from terrestrial planets is possible and occurs regularly. This process may play a role in the escape of water from the atmosphere of Mars and similar bodies, and exoplanets. -- -- Gonzalo Gonzalez Abad Atomic and Molecular Physics Division Harvard-Smithsonian Center for Astrophysics 60 Garden Street, MS 50, Cambridge, MA 02138 Phone: 617-496-7938 Email:ggonzalezabad@cfa.harvard.edu _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list