So here's what I was wondering for quite some time: if, let's say, hypothetically, there were an object approaching Earth at nearly the speed of light, is there

So here's what I was wondering for quite some time: if, let's say, hypothetically, there were an object approaching Earth at nearly the speed of light, is there any way in our frame of reference to even detect it? And is it possible for such an object to exist in our universe, and if not, why? The math seems to work out such that the object the size of a US quarter (5.67g) at 0.999 C will have a relativistic kinetic energy around 2.6MT of TNT.