EXPLORING PLANETS AND MOONS USING GOOGLE EARTH TO CONVEY A SENSE OF PLACE, SCALE, AND TIME

The Google Earth virtual globe is extremely useful for exploring tectonic features on planet Earth. Furthermore, the latest version of the app and API both allow users to switch among Earth, Moon, and Mars with correct 3-D terrains. Following examples posted on the google web site and associated blogs, we are developing extra-terrestrial, self-drive, interactive virtual field trips (VFTs). VFTs to other rocky planets and moons are made possible by draping appropriate ground overlay imagery, however in these cases, the 3-D terrain must be turned off and elevation readings must be ignored. Despite these limitations, VFTs to the Solar System’s planets and moons offer an engaging learning experience in diverse tectonic settings. One hindrance to student learning on non-Earth based VFTs is a loss of sense of place. We are experimenting with a solution that allows students to reference extraterrestrial locations with placemarks and poly-lines representing physiographic provinces or political boundaries on Earth. To help students gain a sense of scale, slices of planets and moons may be juxtaposed for comparison. In addition to exploring the current surfaces and crustal structures of planets and moons, the Google Earth virtual globe can be used to convey past tectonic conditions such as Mars with an ocean or the Moon during Late Heavy Bombardment. In these cases also, the 3-D terrain must be turned off, however a generalized paleo-DEM can be constructed using COLLADA surface models.