ESA's Mars Express obtained images of impact craters in the Tyrrhena Terra region on Mars.

The High Resolution Stereo Camera (HRSC) on board ESA's Mars Express obtained images of this region on May 10, 2007, even providing this perspective view calculated from the HRSC stereo channels.

Tyrrhena Terra sits in the ancient, heavily cratered southern Martian highlands, north of Hellas Planitia, the largest impact basin on Mars. The image shows three impact craters, located at the eastern border of Tyrrhena Terra with Hesperia Planum.

A 21.7-mile (35-kilometer) wide and approximately 3280-foot (1000-meter) deep impact crater dominates the foreground. A steep rim rises up to 1312 feet (400 meters) above the surrounding plains. The crater is surrounded by "ejecta blankets," multiple layers of material thrown out during the impact. The rounded, lobate appearance suggests possible ice- and water-rich subsurface material.

The raised portion of the center of the crater, called "central peak" or "central uplift," likely originated from an elastic rebound of compressed subsurface material after the impact

Another impact crater, 11.8 miles (18 kilometers) long and approximately 2460.6 feet (750 meters) deep, in all likelihood a "double impact crater," is located south of the large crater (to the right in this image). These "double impact craters" form when two objects, possibly fragments of the same object, hit the surface almost simultaneously.

The impact that formed the larger northern crater (in the background of this image), which displays an intact crater wall, occurred after the double impact crater was formed. The ejecta from this later impact reshaped the double impact crater.

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--ESA and SPACE.com Staff

Credit: ESA/DLR/FU Berlin (G. Neukum)