These formations are "rays", found on many rocky bodies. Many craters have some form of ejecta: rocks and*or coloration. What you are asking for is some kind of radial function. Are your craters formed from the TG crater shader or a PF? If the crater shader, one thought is to use the rim part to mask coloration, but that does not get you radial and maybe that's what you are showing. Perhaps some noise stretching in a few directions from a center. In response to your query I tried some coloration approaches using the a SSS 9-sided polygon. With edge at a high percentage there appeared some radial features in the coloration applied to a surface which I tried to get to be a star-shaped mask by using a color adjust, and a distance shader to mask the periphery which tended to show the polygon outline. No success. An involute polygon option on the SSS would do the trick for this approach, its mask could be dirtied with further masking to get an irregular result. BTW your rendering reminds me a lot of Jupiter's moon Callisto.
I had another idea that begets a question. If we were to displace some color spires up from a crater with a PF, and then warp them so they lean beyond the rim in various directions radically (and radially sort of), could the result as a layer get fed to another layer's color function only and used with the displacement thus suppressed, creating some radial color effect? Thus effecting a displacement just for the purpose of computing the altitude for applying color selectively, but not displacing the main terrain.
However in reading a thread on the effect of various warp that dandelio posted, I think the above may not be possible.
Another possibility might lie in trig functions. Sin function will get you concentric formations. I played around with the arc trig functions since they are the inverse but did not achieve anything notable.
Now this just occurred to me: you could use several very high aspect ratio SSSs, perhaps the ellipse, with common centers at the crater center as a mask, and mask them in turn to roughen them. One crater at a time.
For the hyper-realistic minded, note the prominent light-rayed Tycho crater near the bottom in skarlath's posted pic of the moon; the rays do not always converge on the crater itself, and the other prominent light crater above center, Copernicus, has a ray pattern that is closer to a fractal Lichtenberg figure.
