Abell 2218: A Galaxy Cluster Lens
			
		
		
		
			Gravity can bend light, allowing huge clusters of galaxies 
to act as telescopes. 
Almost all of the bright objects in this 
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.
The power of this massive cluster telescope has 
recently allowed astronomers to detect a galaxy at 
redshift 5.58, the 
most distant galaxy 
yet measured.  
This young, still-maturing galaxy is 
faintly visible to the lower right of the cluster core.