West of the immense equatorial gash of Valles Marineris lies a checkerboard region named Noctis Labyrinthus, the Labyrinth of Night. This feature's origins are not certain, but scientists think it began to develop when volcanic activity stirred in the adjoining region of Tharsis, stretching the martian crust and fracturing it.
As cracks and faults opened, ice and water in the subsurface escaped, making the ground collapse. The result today is a tangle of tablelands cut by canyons, troughs, and pits.
This false-color image mosaic was taken by the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter. It focuses on one junction where canyons meet to form a depression 4 kilometers (13,000 feet) deep. The mosaic combines visible wavelength images made during daytime with nighttime infrared images. The nighttime view records the predawn temperature of the surface. This data can tell scientists about the nature of the materials on the ground.
Image credit: NASA/JPL-Caltech/Arizona State University