Edwin Hubble's Galaxy Classification

Edwin Hubble's galaxy classification system groups galaxies based on their shapes. He identified three main types: elliptical galaxies, which are smooth and rounded; spiral galaxies, featuring a flat disk with spiraling arms and a central bulge; and irregular galaxies, which lack a defined shape. This system helps astronomers understand galaxy formation and evolution. The classification is often visual, with galaxies categorized into subclasses reflecting their specific features. Hubble’s work provides a framework for studying the diversity of galaxies across the universe, emphasizing that galaxy structure is linked to their history and development.