Most galaxies in the nearby universe are quite luminous. But some are so faint they’re nearly invisible. Astronomers, using the Hubble Space Telescope in combination with other observatories, identified a galaxy that appears to be almost entirely dominated by dark matter with only a smattering of stars. The galaxy, known as Candidate Dark Galaxy-2 (CDG-2), appears to contain just four globular star clusters (compared to the Milky Way’s 150-plus), and dimly shines with the light of only about 6 million Suns.