The Andromeda galaxy is a colossal marvel in our sky, hosting over 1 trillion stars. Now, astronomers have used the Hubble Space Telescope to capture hundreds of detailed images of our vast galactic neighbor, creating the largest-ever photomosaic of the galaxy. It took over 10 years to create.

This image from the NASA/ESA Hubble Space Telescope features Arp 72, a very selective galaxy group that only includes two galaxies interacting due to gravity: NGC 5996 (the large spiral galaxy) and NGC 5994 (its smaller companion, in the lower left of the image).

Messier 31 is located 2.5 million light-years away from Earth and was a much bigger target in the sky than the galaxies Hubble routinely observes.