SpaceX rocket segment to crash into the moon: What happened?

A discarded upper stage from a SpaceX Falcon 9 rocket completed its uncontrolled journey through space by striking the lunar surface on Wednesday morning. The segment, which had been adrift since the rocket launched from Florida in January carrying two lunar landers, hit Einstein Crater on the moon's western limb at an estimated speed of 5,400 miles per hour. The impact was expected to displace lunar dust, though the resulting plume would be difficult to observe from Earth with the naked eye.

The Falcon 9 is a two-stage reusable rocket system. Normally, the lower stage returns to Earth while the upper stage either re-enters the atmosphere and burns up or falls into the ocean. In this case, the upper stage remained in orbit after completing its primary mission of propelling the lunar landers forward. Because the January mission required greater thrust than typical Earth-orbit operations, the second stage could not be safely deorbited and instead became part of the growing population of space debris orbiting Earth and beyond.

Astronomers determined earlier this year that the uncontrolled rocket segment was on a collision course with the moon. NASA stated there was no danger to Earth and indicated it would continue tracking the booster and later observe the impact site for scientific purposes. SpaceX indicated that for high-energy missions, it performs maneuvers to ensure the second stage complies with safety regulations, though the article text does not provide complete details of this statement.