The bottom of the shell Spiral galaxy similar style two mesh plate finding. The rotating loop style kaenklang Sa Sb Sc subdivisions is based on an arm's length away.
Spiral galaxies form a spiral manner similar plate two halves together style swirl around a central axis. Subdivided into Sa Sb Sc, based on the distance between the arms.
Galaxy, a spiral Spiral appearance resembling two plates mesh if. Style revolves around the central axis. Broken down into Sa Sb Sc by considering the geographical distance of the arm .