A phenomenon observed long enough that they have a word for it e.g. ‘patterned ground’ with the dominant process being freeze-thaw cycles.
At 150 feet down I imagine these polygons are fairly large - on the order of tens of feet across to be able to be imaged by GPR.
It could be dessication or freeze/thaw, but they are below an impact crater. I wonder if they could have been caused by the impact? A layer of stiff buried material at the time of the impact, and ending up looking like shattered glass?
I get a kick how EVERYTHING now-a-days gets referenced to climate change.