There is a great book called Red Thunder in which-—
Spoiler alert!!!!
-—A horribly autistic guy invents a device that allows close to speed of light travel for virtually no cost. At one point a “meteor” slams into the Atlantic ocean off the Florida coast at almost the speed of light, causing terrible mayhem. Turns out it was terrorists that left a few years before and then turned around and came back on a suicide mission.
But the point was that is something is headed toward us at the speed of light, or close to it, we’ll never see it coming, no matter how big it is.
Of course, light speed travel is believed to be impossible, but nobody really knows how close to it you could get.
What about a meteor going half the speed of light?
E=MC^2...................
Won’t happen. Where would the energy come from to accelerate a rock to a significant percentage of c?
Read something like that
World of the Chernyi. A whole series of books - very post-apocalyptic.
In this case, the earth and the moon are sideswiped by ancient alien space junk. It was different if for no other reason than it isn’t about an asteroid/EMP/Evil mad scientist....
Grand adventures follow.
A golfball going 90% the speed of light would probably have enough energy to vaporize the Earth completely/instantly.
However it wouldn’t leave much room for a novel.