Two Views of Galaxy Cluster Cl 0024+17

These two views from the Hubble Space Telescope show the massive galaxy cluster Cl 0024+17 (ZwCl 0024+1652). To the left is the view in visible-light with odd-looking blue arcs appearing among the yellowish galaxies. These are the magnified and distorted images of galaxies located far behind the cluster. Their light is bent and amplified by the immense gravity of the cluster in a process called gravitational lensing.

To the right, a blue shading has been added to indicate the location of invisible material called dark matter that is mathematically required to account for the nature and placement of the gravitationally lensed galaxies that are seen.

Hubble’s uniquely sharp vision allows astronomers to map the distribution of dark matter in space using gravitational lensing.

Credit: NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University)