Hubble tracks down a galaxy cluster's dark matter

Hubble zooms on the sky:
1. Sky map showing the stars as seen by the naked eye (data from ESA's Hippacos satellite)
2. 2.5 degree image from Digitized Sky Survey 2
3. Ground-based image of CL0024+1654 from the Canada-France-Hawaii Telescope (CFHT) using the CFHT12k camera
4. The 39 Hubble Space Telescope images (WFPC2 camera)

Credit: ESA/Hubble (M. Kornmesser & L. L. Christensen)