No, you are almost certainly not going to be hit by a 10-story, 23-ton piece of a rocket hurtling back to Earth.

That said, the chances are not zero. Part of China’s largest rocket, the Long March 5B, is tumbling out of control in orbit after launching a section of the country’s new space station last week. The rocket is expected to fall to Earth in what is called "an uncontrolled reentry” sometime on Saturday or Sunday.

Whether it splashes harmlessly in the ocean or impacts land where people live, why China’s space program let this happen — again — remains unclear. And given China’s planned schedule of launches, more such uncontrolled rocket reentries in the years to come are possible.