Arachnoid (astrogeology)

Arachnoids could be related to volcanos, however it is also possible that different arachnoids are formed by different processes. One possible explanation is that an upwelling of magma from the interior of the planet pushed up on the surface, causing cracks. An alternate theory concerning their origin is that they are a precursor to coronae formation.

Much of what is known about arachnoids is the result of studies performed by C.B. Dawson and L.S. Crumpler.