Or maybe the beginning of Lucifer's Hammer... though I recall the world came out better from the alien invasion.
That was a good book......1978?
I thought astronomers noticed a twisting in the rings of Saturn and tracked it to their big ship. Or maybe I'm thinking Clark's Rama. It's been a while.
"though I recall the world came out better from the alien invasion. "
Yeah, giant ice cream sundays from space pack a wallop.