Hello!
I'm sam, I did a small presentation in front of class (high school, 11th grade) and I had to do LOTS of research. I found a somewhat possible event that could happen.
I'm not sure what you mean by "great rift" but what may happen is that the Earth and sun displaces into the other half of the Milky Way. Same way that when you go in the norther hemisphere on earth and flush a toilet and that the water turns clockwise (i think), and in the southern it goes counter-clockwise, ; the magnetic field around the earth may somehow turn from positif to negatif.
I dunno what would happen then but it would probably make a difference
hope it helps :)