Our galaxy, the Milky Way, is isolated in space but it is not alone. The galaxy closest to us is Andromeda, M31. It is 2.5 million light-years away, which is …
Our galaxy, the Milky Way, is isolated in space but it is not alone. The galaxy closest to us is Andromeda, M31. It is 2.5 million light-years away, which is …