© X-ray: NASA, CXC, CfA, M. Markevitch et al.; Optical: NASA, STScI; Magellan, U. Arizona, D. Clowe et al.; Lensing Map: NASA, STScI; ESO WFI; Magellan, U. Arizona, D. Clowe et al.
This image of the Bullet Cluster is a composite of an x-ray image from the Chandra X-Ray Observatory and a visible light image from the Hubble Space Telescope. The pink clumps are hot gas in the x-ray image that contain most of the normal baryonic matter in the two colliding clusters. The blue areas, on the other hand, show where the mass in the clusters is concentrated based on measurements of gravitational lensing in the optical image. The blue and pink regions are clearly separated, indicating that most of the mass in the clusters is dark matter. (Unit: 10)