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Project Progress

Explaining the persistence of volcanism on Mars is a challenging target for geodynamic models, which form the basis for understanding plate tectonics and habitability on rocky planets around other stars. UH NAI team member Eric Gaidos is collaborating with us on a study of rocky extrasolar planet geodynamics, extrapolating from solar system observations to extrasolar super-Earths and first results were published this year (Kite et al., 2009). We find that planets larger than Earth that have plate tectonics will be volcanically active for the age of the Universe. We show that plate tectonics, however, is not favored on large planets. Our models predict Mars should no longer be volcanically active. The occurrence of young volcanism suggest that the Martian mantle is layered and the lower layer provides a heat source that extends the period over which Mars remains volcanically active.

Our collaboration with UH NAI member Gaidos continues. The discovery of the close-in rocky exoplanet CoRoT-7b has spurred us to model the surface temperature distribution on tidally-locked planets whose dayside is covered by magma. Although CoRoT-7b is not in the habitable zone, understanding the composition of close-in Earth-sized extrasolar planets can provide clues on the frequency of truly Earth-like planets.