An Etymological Dictionary of Astronomy and Astrophysics

In Saturn’s rings, changing structures in the radial direction. It is thought that gravitational forces alone cannot account for the spoke structure, and it has been proposed that electrostatic repulsion between ring particles may play a role.

Etymology (EN): M.E.; O.E. spaca “spoke,” related to spicing “large nail,” from P.Gmc. *spaikon (cf. O.S. speca, O.Fris. spake, Du. spaak, O.H.G. speicha, Ger. speiche “spoke”).

Etymology (PE): Parré “a rod that extends from the hub of a wheel to support or brace the rim.”