Leaf-like structures in Antoniadi impact crater

This image, captured on 25 March 2020, shows the bottom of the 400 km in diameter Antoniadi impact crater, which is located in the northern hemisphere of Mars in the Syrtis Major Planum region. The blue colour of the image, centred at 21.0°N, 61.2°E, does not represent the real colour of the crater floor but highlights the diversity of the rock composition inside the impact crater.

In the centre of the image are dendritic structures which look like the veins on oak leaves. These structures, evidence of ancient river networks in this region, protrude from the surface, unlike channels, which are usually sunken in the surface. This is because the channels were filled with harder material – possibly lava – and over time the softer rocks surrounding these branching channels have been eroded, leaving an inverted imprint of this ancient river system.