As an example , the Milky Way Galaxy is roughly 100,000 light years in diameter , and the nearest sister galaxy to the Milky Way , the Andromeda Galaxy , is located roughly 2.5 million light years away .
As an example , our Milky Way Galaxy is roughly 100,000 light years in diameter , and our nearest sister galaxy , the Andromeda Galaxy , is located roughly 2.5 million light years away .