New photos from Mars suggest that Curiosity is traversing an ancient river bed and is the first recorded evidence of water-transported gravel on Mars.
NASA says that from the size of various features such as the stones themselves, their wear characteristics and other erosion that the stream had a speed of around 3 feet per second and anywhere from ankle to hip deep.Similarly, the size of the gravel is such that it could not have been transported by wind from its source, thought to be from the rim of the crater where the stream apparently widens into an alluvial bed – like a river estuary or delta.
While other evidence of running water has been found on Mars by other missions this is the first evidence of gravel transport and conglomerate rock formation as a result of it. NASA might use Curiosity’s instruments to discover more about the local region’s geology by analysing a sample of the sedimentary matrix that holds the conglomerate together. Since the gravel contained in the rock comes from further afield, its an easy way to discover more about the region that Curiosity is in without having to travel itself.
This article summarised from materials provided by NASA.