Down in Chukhung Crater

Chukhung is a 45 kilometer-diameter, central pit crater in Tempe Terra, having likely formed 3 billion years ago. The southern portion of the crater floor hosts a large viscous flow feature that is hypothesized to be a glacier. There are sinuous ridges that emanate from the margin of the flow feature toward the center of the crater. These ridges could be evidence of glacial meltwater preserved in the form of eskers, inverted channels formed when the softer sediments surrounding the channel deposits are eroded away. It is unclear whether the conditions for wet-based glaciation ever existed on Mars, but these ridges could be evidence that it once did. https://photojournal.jpl.nasa.gov/catalog/PIA23528