This page contains unmarked spoilers! Read at your own risk!: Proceed
The Carbon Anomaly is a unique, moonlet-like formation that can appear within the rings rarely.
This POI currently acts only as an astrogation point, and like moonlets cannot be destroyed. However, if scanned with a microseismic recon drone, it shows a carbon and calcium content, implying it has some biological formations, hence the skull-like features. The usage of the spooky music when nearby also further implies such.