Speaking of compaction, look how strikingly smooth and vertical large portions of the far wall of the trench are. No doubt those top-notch soil scientists at JPL can tell a lot about the soil properties from features like that -- as well as from the way "nodules" of compacted soil cling to the trench wall.
Here on Earth, we would expect those walls to crumble and collapse somewhat as the exposed soil dries out. Wonder how those walls will change over time on Mars -- and what those changes (if any) will tell the soil guys...
Very interesting stuff!!
