The light from the Andromeda Galaxy — the most distant object visible to the naked human eye — left its source about 2.5 million years ago, which means when you look at it on a clear night, you are seeing light that began its journey to Earth around the time th - Space Daily

The light from the Andromeda Galaxy — the most distant object visible to the naked human eye — left its source about 2.5 million years ago, which means when you look at it on a clear night, you are seeing light that began its journey to Earth around the time th Space Daily