I'd recommend reading the book https://en.m.wikipedia.org/wiki/The_Engines_of_God

I'd also recommend The Three Body Problem trilogy, specifically the second book, The Dark Forest.

I'm about halfway through, and can second the recommendation. I think I see a potential twist, but I want to see how it actually plays out in the end.

I wonder how you steer that thing. As in, earth is a pretty small target from a few light years away. In the case where you want to visit some planet peacefully, you spend the second half of the journey decelerating so you can do the needed corrections easily due to your lower speed, but if you are close to your target at a significant fraction of light speed, it's hard to change your course.

I've watched Armageddon. All you need is a nuke and Bruce Willis.

Mr Willis is 67 years old. I suspect that any incoming attack asteroids are more than 13 years out (it just seems statistically improbable that one will show up sooner than that - I don't have any data on incoming bogies), and asking a >80 yo person to go take out asteroids seems like a plan destined to fail.

Point being, we should hurry up and create a bunch of Bruce Willis clones before it's too late. The future of humanity depends on it!

Please keep comments like this on reddit. Thank you

No, you need Harry Stanton. Bruce is just an actor.

Doh! Harry Stamper