[Previous] | [Session 27] | [Next]

[27.11] Effect of Giant Impact on Planetary Atmospheres

T. J. Ahrens, A. H. Shen, S. Ni (California Institute of Technology)

Theories of planetary growth via impact accretion lead to both co-accreting primitive atmospheres, as well as, to impacts of increasingly larger planetesimals. Thus, giant impacts occurred in the presence of early atmospheres. Approximating a giant impact as a sub-surface giant explosion on a fluid elastic planet, the resulting body- and surface-waves are calculated via normal-mode summation, and, the effect of the ground motion on the overlying atmosphere is calculated as a function of position. The expected convergence of anti-podal surface waves is demonstrated. Atmospheric escape for the Earth begins at 10²⁷ J and 2x10³², 3x10³² and 3x10³⁰ J remove 50% of the atmospheres of Earth, Venus and Mars.

[Previous] | [Session 27] | [Next]

Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.