Hubble Spots a Galaxy 99.9% Dark Matter

Astronomers using data from the Hubble Space Telescope, Euclid and the Subaru Telescope identified Candidate Dark Galaxy-2 (CDG-2), a distant galaxy that appears to be about 99.9% dark matter and extremely star-poor. The galaxy’s mass is inferred from a halo of four globular clusters, suggesting a rare, almost-dark galaxy that could provide a cleaner probe of dark matter—though further observations, including with the James Webb Space Telescope, are needed to confirm its dark matter content.