Drat. We're gonna miss it.

I've waited all my life for this August's total solar eclipse. But there's an even bigger show coming. Unfortunately, I'm going to miss it.

Every winter I have to find the Andromeda Galaxy, the closest galaxy similar to the Milky Way, all over again. Once I do, I can make it out- barely- with the naked eye for the rest of the winter. It's spectacular in a pair of 7x50 binoculars.

Well, M31, as the Andromeda Galaxy is known (its designation in the catalog of  French astronomer Charles Messier, compiled in 1771 to help comet hunters avoid mistaking other cosmic fuzzballs for comets) and our own Milky Way are headed for a collision. Don't worry; you're safe- or would be if you were alive 3.75 million years from now when it actually happens. The space between stars is so huge that stellar collisions are unlikely. But the nighttime sky will be in for some major changes as the two spiral galaxies merge into one huge elliptical galaxy.

Here's how it's going to go down.