Part 12/15:
Our neighboring spiral galaxy, M31, is perhaps the most familiar due to its visibility to the naked eye from dark skies. At just 2.5 million light-years away and spanning 220,000 light-years, it contains roughly twice the number of stars as our Milky Way—estimated at one trillion. High-resolution images reveal dense star fields and intricate dust lanes, offering a detailed view of a galaxy destined to collide with the Milky Way in several billion years.