How far away is the nearest galaxy to the Milky Way (excluding the Sagittarius dwarf) in light years?
25,000 light years away. Recent evidence shows that the Canis Major dwarf is probably the closest galaxy to us after the Sagittarius Dwarf (which seems to be colliding with the other side of the Milky Way Galaxy). The Canis Major Dwarf probably includes Messier 79, a globular cluster in Lepus. M54 is believed to be a part of the Sagittarius Dwarf.