Thanks for pointing out this intriguing formation. I'm going to go out on a limb and suggest this is not an impact structure at all, not a "buried crater." Instead, I suspect this structure -- and many like it -- are caused by internal forces.

I suspect that volatiles, mostly liquid water, collect below the surface and that they then emerge at the surface, often due to heating from below. Such emergence to the cold near-vaccuum of the surface would usually be explosive, leading to the removal of significant areas of the surface. Water and other volatiles may cause portions of the surface to founder.

In this instance, we see considerable evidence of flow within the pit. Something most certainly did flow here, and not all that long ago, either. I suspect it was water, released from the interior. For a time, it is possible there could have been a localized and temporary "warm, thick" atmosphere (mostly water vapor) sufficient to allow surface water flow. Such events could take place today.

But. What do I know? Not much!

Cheers, B R Felix