https://science.nasa.gov/missions/hubble/nasas-hubble-traces-hidden-history-of-andromeda-galaxy/
"Now, a century later, the space telescope named for Hubble has accomplished the most comprehensive survey of this enticing empire of stars. The Hubble telescope is yielding new clues to the evolutionary history of Andromeda, and it looks markedly different from the Milky Way’s history."
Video on Youtube by NASA: