In the 1920s, astronomer Edwin Hubble developed a scheme
for classifying galaxies by shape and structure. Elliptical,
spiral, and barred spiral galaxies have descriptive
names. Galaxies with no apparent structure are classified
as irregular, and galaxies that have definite structures
but don't fit neatly into the existing categories are
! Click each galaxy icon to view a telescopic image of that type of galaxy.