This is interesting, a recent HiRISE photo from the Mars Reconnaissance Orbiter spacecraft showing an oval pit or crater with an opening in the bottom (cropped here from one of the larger images) near Galaxias Chaos on Mars. The opening is also oval, and you can see some sand dunes on the bottom. How did it form? More images are available here.
Paul Scott Anderson is a freelance space writer with a life-long passion for space exploration and astronomy. He currently writes for The Spaceflight Group, AmericaSpace and Examiner.com. His own blog The Meridiani Journal is a chronicle of planetary exploration.
The thing in the middle looks almost like a glacier. What is it? A meteorite fragment?
looks like a pool of water, judging by shadows cast on level surface. This should be below the 6mBar elevation, Martian sea level, so liquid water can exist.
To my eyes, the thing in the middle looks like it is HIGHER, not LOWER, than the surrounding area inside the crater. That means it must be a solid mass, not liquid. An ice glacier? A meteorite fragment?
I think it’s blueish fragments of something that hit and caused the crater. One can clearly see a piece on the side as well