UNDERSTANDING VOLCANISM ON TERRESTRIAL PLANETS AND MOONS USING VIRTUAL GLOBES AND COLLADA MODELS

Recent space missions to planets, moons, and asteroids have returned a wealth of data regarding volcanism in the solar system, including surface photography, altimetry, and thematic mapping. However, for a full understanding of the origin and evolution of volcanic systems, three- or four- dimensional modeling is critical. We have previously reported on methods for visualizing the Earth's interior using virtual globes in combination with emergent crustal models and we here present results from application of these methods to other terrestrial bodies. We represent planets and moons by draping surface imagery over the Google Earth virtual globe and we create local sample topographies using Collada models. Keyhole Markup Language (KML) and Javascript controls determine the appearance of the planet or moon's interior and HTML code is embedded in placemarks in order to link to specimen images and analyses stored on external web sites. Local models reveal crustal-scale structures and dynamics whereas larger global models are employed to visualize the mantles and cores of planets and moons. Our methods effectively demonstrate the different scales of volcanism arising from planetary differentiation, plate tectonics, plume tectonics, impacts, and tidal stresses, and help overcome misconceptions such as the roles of solid versus fluid flow in deep mantle plumes. Comparisons of the relative dimensions of planetary and lunar mantles help students relate style of volcanism to secular cooling. Lesson plans are presented comparing the Hawaiian volcanic chain on Earth and the Tharsis region on Mars. Speculation regarding volcanism on super-earths is constrained by examination of theoretical models of exoplanets.