Explanation:
Almost every object in the above photograph is a galaxy.
The Coma Cluster of Galaxiespictured above
is one of the densest
clusters known - it contains thousands of
galaxies.
Each of these galaxies houses billions of stars -
just as our own Milky Way Galaxy does.
Although nearby when compared to most other
clusters,
light from the Coma Cluster
still takes hundreds of millions of years to reach us.
In fact, the
Coma Cluster is so big it takes light
millions of years just to go from one side to the other!
The above mosaic of images of a small portion of
Coma was taken in unprecedented detail by the
Hubble Space Telescope
to investigate how galaxies in rich clusters form and evolve.
Most galaxies in Coma and other clusters are
ellipticals, although some
imaged here are clearly spirals.
The spiral galaxy on the upper left of the
above image can also be found as one of the bluer galaxies on the upper left of
this wider field image.
In the background thousands of unrelated galaxies are
visible far across the universe.
digg_url = 'http://apod.nasa.gov/apod/ap080616.html'; digg_skin = 'compact';
Note: APOD started thirteen years ago today.
