Martian canyon, 3D image based on satellite data. Perspective view of a tributary canyon of Valles Marineris, the largest canyon system on Mars. The canyon system is thought to have been formed by a combination of tectonic activity and water erosion. The canyon walls are many kilometres high. This image was generated using infrared data from the Mars Odyssey spacecraft's Thermal Emission Imaging System, and topographical data from the Mars Global Surveyor spacecraft's Mars Orbiter Laser Altimeter, both of which are in orbit around Mars.