James Webb Space Telescope

This is something that I've wondered about

I'm sure galaxies colliding/merging is a very slow process, but if it was happening right now, how would we here on Earth perceive it?

Just the stars being different or other effects?
The Earth would be, more than likely, a barren rock rock when the Milky Way collides with another galaxy. Hell, Europa would probably be the most habituated planet in our solar system by then.