Displayed in this Hubble tuning fork diagram is a sliver of the universe today. The diagram separates the universe into spiral, elliptical and lenticular galaxies. The ellipticals are illustrated on the left, the spirals are on the right, and the lenticulars are in the middle. "Our local universe displays big, fully formed and intricate galaxy shapes," said ESA. Present-day galaxies vary in form and are classified via a system called the Hubble Sequence, which categorizes galaxies according to their morphology and star-forming activity.