Nearby Colliding Galaxies
A galaxy-galaxy collision may take about 1 billion years to
occur. Hence, we cannot actually witness a full merger taking place.
However, we can take snapshots of different mergers at various stages
of the encounter. Below, there are several such examples. The first
three images were obtained online from the
Digitized Sky Survey, and are displayed as negatives to make it
easier to see details.
To view an image at higher resolution, please click on the image.
The Antennae : this is a classic example of a merger in the early
stages. These galaxies are currently separated by about 50,000 light
years (15 kpc).
"Atoms for Peace" : this is typical of a late-stage merger.
This appears to be an on-going merger of two massive spiral galaxies,
in the process of forming a single elliptical galaxy.
Arp 220 : this merger appears to be nearly complete.
Note that these galaxies are roughly 250 million light years away from us.
Recent images of the Antennae were taken with the Hubble Space
Telescope. The image is given below. Click
read a CNN story on this image.