(via APOD: 2012 August 12 - Spiral Galaxy NGC 4038 in Collision)
NGC 4039 took it upon itself to crash right into spiral galaxy NGC 4038 in the upper left. The resulting cataclysm of gravitational restructuring, gas and dust compression (leading to a lot of sudden star formation, and just as sudden stellar explosions as the high-mass stars burn through fuel rather quickly), and overall chaos is familiarly known as The Antennae.
(You can see the antennae, right?)
Of equal interest to this forebear of what our galaxy will go through in a few billion years when Andromeda comes crashing through is the credit line:
Image Credit: Data Collection: Hubble Legacy Archive; Processing: Danny Lee Russell
That is, the data for this image was collected by Hubble and stored in the Hubble Legacy Archive, but the final view here was processed through the FITS Liberator and image editing software.