Martian water erosion. Channels on a crater wall on Mars, thought to indicate the presence of liquid water in its recent history. These features are thought to have been formed by groundwater seepage and surface runoff. The sharpness of the features and the lack of small impact craters imply that they are very young. This means that liquid water may still exist below the surface of Mars, which would provide a viable habitat for life. These features are on a crater wall near Gorgonum Chaos in Mars' southern hemisphere. This four kilometre wide image was taken by the Mars Orbiter Camera on the Mars Global Surveyor spacecraft orbiting Mars. Data analysed in 2000.