Remains of Ancient Mars Lake Seen in Satellite Photos

The Eberswalde crater on Mars (smaller semicircle on right) used to be a water-filled lake, satellite data reveal. On the left is the larger Holden crater, which impacted later.

Telltale delta features, such as squiggly lines that represent water feeder channels, can be seen in this Mars Express photo of Eberswalde Crater on the Red Planet