A Sky Full of Dust Over CTIO

Is that a cosmic crack in the sky? No, it’s just the colossal clouds of dust known as the Great Rift! In this stunning image of the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab, the Great Rift’s dark clouds appear to slice the Milky Way’s river of starlight in half.

Running vertically through this image, the Great Rift reminds us that our Milky Way is not simply a collection of stars. Our home galaxy is also host to a staggering amount of interstellar dust. In fact, the Great Rift alone contains a million Suns’ worth of it! This opaque cloud complex is made of ultrafine particles around ten times smaller than pollen. Despite their diminutive size, together they can obscure the light from the brightest part of our galaxy. 

Another ‘cloud’ of dust is also visible from this view. Running diagonally downward from the top left of this image is a band of interplanetary dust. Its white glow is known as zodiacal light. Unlike the Great Rift which is dark and far beyond our cosmic neighborhood, this dust is bright and within our Solar System. Its faint white glow is caused by reflected sunlight. To the upper left in the zodiacal light is a triangle of the three planets (from left to right) Venus, Mars and Saturn.

This photo was taken as part of the NOIRLab 2022 Photo Expedition to all the NOIRLab sites. Tomas Slovinský, the photographer, is a NOIRLab Audiovisual Ambassador.