These mysterious beach formations, like the ones spotted on a beach in Dorset, England, are called beach cusps – and one reason they’re mysterious is that scientists still aren’t completely sure how they’re formed.
Beach cusps, which often appear during or after storms, are unusual because their spacing is uniform and regular. If you don’t believe in aliens, there are two prevailing theories about their formation. The first is the ‘standing edge’ theory, which involves interactions between normal waves approaching the shore and “edge” waves, which form perpendicular to the shore. The interactions between these waves form regularly-spaced points of different wave intensity. The other theory is the self-organization theory, which claims that cusps are the result of regular wave, current, and sand interactions over time that create feedback loops. Many scientists believe that both of these theories might work in unison to create these curious structures.