If the rock had passed a couple of meters to either side, it would have missed them entirely and they wouldn’t even have known it was there. In the Earth’s atmosphere, of course, it would have been a different story. The rock would have dissolved in a bright streak, turning most of its kinetic energy into heat. The air in its immediate vicinity would have gotten warmer for a bit. Had it happened at night, keen observers might have seen a streak of light. When the same thing happened on a large scale, all over the Earth, the air became so hot that it glowed, as it was doing now.