Weak gravitational lensing

This animation shows how weak gravitational effect from dark matter distorts the shapes of distant background galaxies. Note how the shape of the galaxy changes from round to elliptical. The map was created by using this technique, and analysing the distorted shapes of half a million distant galaxies. Such subtle distortions were then used to reconstruct the mass distribution along Hubble’s line of sight.

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