Great Rift (astronomy)

In astronomy, the Great Rift (sometimes called the Dark Side, Dark Rift, or, less commonly, Dark River) is a series of overlapping, non-luminous, molecular dust clouds that are located between the Solar System and the Sagittarius Arm of the Milky Way Galaxy at a distance of about 100 parsecs or about 300 light years (2×10 miles or 3×10 kilometers) from Earth. The clouds are estimated to contain about 1 million solar masses of plasma and dust.