Located in the constellation Corvus, these two spiral galaxies
are in the long process of merging. About 600 million years ago,
attracted to one another by gravity, the two galaxies passed through
each other (the vast distances between stars means that in galactic
"collisions", actual star-crashes would be rare). As the gas and dust
was forced together in this encounter, new nebulae and star clusters
formed, visible as bright knots in the galaxies. As the galaxies
continue to circle closer and closer to each other, they will
eventually form a single galaxy in about 300 million years. This process
is similar to what will happen between our Milky Way Galaxy and the
Andromeda Galaxy in the distant future.

In the case of NGC 4038 & 4039, the gravitational forces of the merger
have caused long trails of gas, dust, and stars to form from each of the
galaxies, giving the common name for this pair, The Antennae Galaxies.
If you look closely just above the end of the right-hand "antennae", you
will see a very faint patch; here, a new dwarf galaxy is forming out of
this scattered material (designated NGC 4038S).

There is a second interacting pair of galaxies in this image. At the upper
right is NGC 4027, a spiral galaxy that seems to have only one arm. Below it
and to the right is the smaller NGC 4027A, with a clearly distorted shape.
It is likely that the odd shapes of both these galaxies is due to the gravitational
interaction of the two.

Image data:
Camera: Canon 350 XT (modified)
Exposure: ISO 800, 5 minutes x 51
Telescope: 10" Schmidt-Newtonian, Baader MPCC