The bad news is the Milky Way galaxy is going to collide with the Andromeda galaxy (also referred to as M31). The good is that it will not occur for four billion more years. What this means in terms of the question -- what is the distance between these two galaxies -- is that the answer is dynamic. Currently, according to the National Aeronautics and Space Administration (NASA), the two galaxies are 2.5 million light years apart. Given that the Sun has been calculated to be half-way through its life cycle of about 9 billion years, that means that the Sun -- a star of medium dimensions -- will die out roughly the same time that the two galaxies collide. The Sun's death will, of course, mean the extinction of life as we know it on the Earth, so the Solar System is scheduled for major structural transformations from whichever event occurs first.
but the universe is expanding!
WHY WILL IT COLLIDE!!!!!!!!!!!!!!