Sculpted by Wind and Water

Mars Express above the thin Martian upper atmosphere successfully achieved orbital insertion on Christmas 2003.
Credit: NASA/JPL

The European Space Agency’s Mars Express has taken an new photograph of Nicholson Crater, located at the southern edge of Amazonis Planitia on Mars. This crater is 100 km (62 km) across and has a very large raised central mount. Large craters often have this kind of central peak, which forms when material rebounds after a meteor impact, but Nicholson Crater’s peak is heavily eroded by wind and water.

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, shows Nicholson Crater, located at the southern edge of Amazonis Planitia on Mars.

The HRSC obtained this image during orbit 1104 with a ground resolution of approximately 15.3 meters per pixel. The scene shows the region around Nicholson Crater, at approximately 0.0° South and 195.5° East.

Nicholson crater.
Credit: ESA

Nicholson Crater, measuring approximately 100 kilometers wide, is located at the southern edge of Amazonis Planitia, north-west of a region called Medusae Fossae.

Located in the center of this crater is a raised feature, about 55 kilometers long and 37 kilometers wide, which extends to a maximum height of roughly 3.5 kilometers above the floor of the crater.

At present, it is still unclear how this central feature was shaped and what kind of processes led to its formation. It is thought that the remnant hill could be composed of material from underground or was built as a result of atmospheric deposition.

The tall feature in the center of this hill is the central peak of the crater, which forms when the surface material rebounds’ after being compressed during the formation of an impact crater.

However, it is clear that this feature has been heavily sculpted after its creation, by the action of wind or even water.