On October 3, 1997 the Mars Global Surveyor took this photograph of the western Tithonium Chasma/Ius Chasma portion of the Valles Marineris on Mars. The image, despite poor light, shows canyon floors, in shadow, and highlighted cliffs. Revealed are layers of bedrock that vary in thickness. This image changes the understanding of the surface of Mars from one of sedimentary deposition to a more complex story of development.