One Definite Apocalypse

Say hello to the Andromeda Galaxy -- in many ways our Sister galaxy in the local area. The only other big galaxy near us for many hundreds of thousands of light years.

The Milky Way and Andromeda galaxies both have much smaller galaxies orbiting them (see the smudge in the foreground above), and the two galaxies orbit each other.

However, they are also drawing closer together, and given that Andromeda has quite a bit more mass than the Milky Way, eventually the two galaxies will collide, and merge, with Andromeda taking the dominant role. At that time (approx 3 Billion years hence), our planet's destruction is likely. Not because the sun will be destroyed necessarily, but because of the great turmoil in the interstellar medium.

So, don't worry about the end of the sun (red giant stage in approx 5 Billion years) -- our world will be destroyed well before then!