Not everything shooting through space is a good thing. Here are two MIRV tests. These all came from one rocket, as I understand it, and hit targets in the pacific at high mach speeds. The trails are marked by, I think, incandescent plasma as a result of heating from such fast objects. It is shocking that they can maintain such high speeds for so long - all the way to impact it seems. Granted they may be 1000 lbs each, and inside a very compact package that is aerodynamic, but still machs of 5, 10, or even more are hard to sustain without tons of rocket power. Much of nuclear war is still unknown, probably for the best.
This last image shows what the two tests would have done to New York.