Terby (crater)

Terby is a crater on the northern edge of Hellas Planitia, Mars. The 174 km diameter crater is centered at 28°S, 73°E with an elevation of −5 km. It is named after François J. Terby. It is the site of an ancient lakebed and has clay deposits.


  • Map of Iapygia quadrangle with major craters. The crater Terby is of great interest to scientists because it contains many rock layers.

  • Layers in Terby crater, as seen by HiRISE. Layers may have formed when the Hellas basin was filled with water.

  • Terby Crater layers as seen by HiRISE.

  • Mounds in craters like Terby are formed by the erosion of layers that were deposited after the impact.