Click for original image.
Today’s cool image illustrates the complex explanations scientists sometimes have to come up with explain the strange geology seen on Mars. The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 30, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a whitish “ridged flow-like feature” that appears to exit out of the massive hill to the west.
The white dot on the overview map above as well as in the inset marks this location, smack dab inside the 2,000-mile-long strip of glacier country in the Martian northern mid-latitudes. As you can see from the inset, that massive hill is actual the foot of a large apron of material, likely ice-infused, that has sagged down from the large 5,400-foot high mesa to the west.
The white material is likely what the scientists call an inverted river. Once it was a channel in which either water or ice flowed. With time the weight of that material compacted the riverbed so that it was denser than the surrounding terrain, much of which was likely soft anyway because of a high ice content. When that surrounding terrain eroded away, the riverbed resisted that erosion, and instead became the raised ridge we now see.
