... The separation between the cloud layers and the height variations have been exaggerated. ... The layers probably include carbon dioxide ice, water ice, rock and dust. ... An eerie blue glow and ominous columns of dark dust highlight M78, a bright reflection nebula in the constellation of Orion. ... Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. ... Journey to the Center of the Galaxy . ... Blue Marble 2000 . ...