Space junk and meteoroids are falling to Earth every year, posing a growing risk as they re-enter the atmosphere at high speeds. Researchers are using infrasound sensors to track these objects, including bolides,

A spacecraft launched by the Soviet Union in 1972 is due to come crashing back into Earth's atmosphere around May 10 and nobody knows where it will land.

While it made it into space successfully, the spacecraft wasn't able to complete its journey after something went wrong. Most of the remains of the rocket eventually came back to Earth within the 10 years that followed.