Astronomy Picture of the Day . The Dark River to Antares . ... Credit: Jason Jennings Explanation: Connecting the Pipe Nebula to the colorful regon near bright star Antares is a dark cloud dubbed the Dark River , flowing from the picture's left edge. ... Above it, bright blue double star Rho Ophiuchi is embedded in one of the more typical bluish reflection nebulae, while red emission nebulae are also scattered around the region. ... Publications with keywords: dark - emission - nebula . ...