The Pinwheel Galaxy

The Pinwheel Galaxy (Messier 101 or NGC 5457).

 

The Pinwheel Galaxy is located about 21 million light years away in the direction of the Ursa Major (Big Dipper) constellation. This vibrant astronomy picture combines data in the infrared, visible, ultraviolet and x-rays from four of NASAs space telescopes.

For details about what the various colors represent, 

see http://www.spitzer.caltech.edu/

Astronomy Pictures - Pictures of the Universe