Abell 2218: A Galaxy Cluster Lens
Gravity can bend light.
Almost all of the bright objects in this
recently released
Hubble Space Telescope image are galaxies in the
cluster known as Abell 2218.
The cluster is so massive and so compact that its
gravity bends and focuses the light from galaxies that lie behind it.
As a result,
multiple images of these background
galaxies are distorted into long faint arcs -
a simple lensing effect analogous to viewing distant street
lamps through a glass of wine.
The
cluster of galaxies Abell 2218 is itself about
three billion light-years away in the northern
constellation
Draco.