Why is a 4,500-kg SpaceX rocket about to crash into the Moon at 8,700 km/h?

A discarded 4,500-kg SpaceX rocket is on a collision course with the Moon at 8,700 km/hour. The rocket stage was launched in January 2025 and ended up in a complex orbit because it didn't have enough fuel to return to Earth or remain in a stable orbit. Its trajectory was gradually altered naturally until a Moon collision became unavoidable.