Tag: spaceflight

Cool image time! The image on the right, cropped from the original to post here, was taken by Mars Odyssey on May 13, 2018, and shows what clearly looks like a point where a south-to-north drainage broke through a cliff wall to allow a liquid to flow down into the larger and deeper east-west flowing canyon.

The caption at the website for this image provides only a little analysis.

The right angle intersection of the depressions in this VIS image is one of the graben that form Sacra Fossae. The fossae are located on Sacra Mensa, near the beginning of Kasei Valles. Graben are depressions caused by parallel faults where a block of material drops down along the fault face.

According to this geological interpretation, the depressions initially formed due to this geological process. The image however suggests that a flow of liquid also played a part.

This region, indicated by the white cross on the map to the right, is part of the vast drainages that flow down from Mars’ four giant Martian volcanoes. It is located north of Valles Marineris, the largest of all these drainages. This region is also where you find a lot of chaos terrain, which is what the hummocky depression at the bottom of the image resembles. Much of this mysterious geology is thought to have been formed by the liquid water that is theorized to have once flowed down from the volcanoes. Here, it appears that the liquid ponded in the depression at the bottom of the image until it found a path along the north-south graben to break through into the east-west deeper graben.

Time for another cool image! The image on the left, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on May 31, 2018, and shows a very strange layered mesa sitting in what looks like a crater or collapse feature. If you click on the image you can see the entire picture.

The location of this image is out in the middle of the vast northern plains of Mars. This region has few pronounced features, and generally sits at a lower elevation to the rest of Mars. It is suspected by some scientists that an intermittent ocean was once here, and that we are looking at the floor of a now dry sea.

This image was part of the July image release from MRO, and thus included no caption. They simply refer to it as a layered feature. It sits about a half mile (about 800 meters) to the west of a rough and indistinct cliff that drops down into an area of rougher terrain. This suggests that if this was formed by an impact, it cut down into that lower rougher layer, and since the impact there has been some upwelling from below creating the layered mesa.

I would not take my hypothesis very seriously, however. This feature could have nothing to do with an impact. It might also have been a mesa that now sits in a collapsed sinkhole. Or not. I could come up with many theories, all of which are likely wrong. What I do see here is something that geologically is very strange and baffling.