... Credit Copyright: NASA , ESA , and the Hubble Heritage ( STScI / AURA )- ESA / Hubble Collaboration Explanation: Except for the rings of Saturn , the Ring Nebula (M57) is probably the most famous celestial band. ... The recent mapping of the expanding nebula's 3-D structure , based in part on this clear Hubble image , indicates that the nebula is a relatively dense, donut-like ring wrapped around the middle of a football-shaped cloud of glowing gas. ... Bright Planetary Nebula NGC 7027 from Hubble ....