This STL file is a topographic model of a portion of Valles Marineris with vertical exageration, derived from data collected by the MOLA altimeter onboard NASA's Mars Global Surveyor mission. Printed at its default size (8cm across) this model cover an area approximately 1000km across at a scale of 12.5 million to one ( 1 cm = 125 km ) Data Credit : NASA/MOLA Science Team