The Infrared Universe: Galaxies
Andromeda is the nearest spiral galaxy to the Milky Way, around 2.5 million light-years away. Once thought to be a twin of our galaxy, its different structure is very evident in infrared light. While it is a spiral galaxy, its dust falls largely in a huge ring structure, possibly caused by gravitational interactions with its smaller satellite galaxies.
CREDITS: Visible: NOAO/AURA/NSF. Infrared: NASA/JPL-Caltech/K. Gordon (University of Arizona).