Dark flows run down the slopes of Stevinus A crater on the Moon in this detail of an image from the LRO’s camera. Large boulders that have rolled downhill appear to have interrupted the flow in at least one spot in this image.
It’s still not exactly known whether these features in Stevinus A are the result of impact melt or dry material that flowed like a liquid after a lunar seismic event.
Read more about this image on the LRO site, and see the full zoomable LRO image here.
Image credit: NASA/GSFC/Arizona State University
Lights in the Dark 