[Credit and Copyright: NASA, JPL-Caltech, UCLA, MPS/DLR/IDA]
That is clearly a citadel in the center and an outlying military base. :-)
It looks like a sunken crater.
Perhaps there is an aeons old development of a powder/rock crust that overlays sub-surface ice (Water, methane, whatever) underneath. Over millennia the ice sublimates or bleeds off, or forms compounds that cause it to lose volume, and the crust is no longer supported. An asteroid strikes the surface, the strike causes a collapse of the crust area surrounding the impact point, there is a blowout of subterranean gas that pushes out out remaining ice crystals or gas, or something that precipitates at the surface and causes that extra sparkley sugar frosting coating at the impact point, and from several nearby holes.
It looks like a sunken crater.
Perhaps there is an aeons old development of a powder/rock crust that overlays sub-surface ice (Water, methane, whatever) underneath. Over millennia the ice sublimates or bleeds off, or forms compounds that cause it to lose volume, and the crust is no longer supported, or only at points. An asteroid strikes the surface, the strike causes a collapse of the crust area surrounding the impact point, there is a blowout of subterranean gas that pushes out out remaining ice crystals or gas, or something that precipitates at the surface and causes that extra sparkley sugar frosting coating at the impact point, and from several nearby holes.
Looks like the title of the article was wrong......