A new image of Earth’s nearest large galactic neighbor, the Andromeda Galaxy, is aglow with the light of more than 100 million stars. Scientists took long looks at a portion of the spiral galaxy’s disk, then published a panorama of 7,398 incredibly high-resolution Hubble Space Telescope images (above). In it, there are 1.5 billion pixels spanning 40,000 light-years. But the galaxyscape is more than just a pretty picture: It’s providing clues about Andromeda’s evolutionary history that teams are using to piece together how the galaxy formed and grew up. Among those clues are hints that Andromeda may have had a much more violent past than the Milky Way, and that older stars in its disk are behaving