Five days of observations produced the altogether 39 Hubble Wide Field and Planetary Camera 2 (WFPC2) images required to map the mass of the galaxy cluster Cl0024+1654. Each WFPC2 image has a size of about 1/150 the diameter of the full Moon. In total, the image measures 27 arc-minutes across, slightly smaller than the diameter of the Moon.
The observed warped shapes of more than 7000 faint background galaxies have been converted into a unique map of the dark matter in the cluster.
The images were taken through a red filter and have been reduced a factor of two in size.