A SpaceX rocket piece floating in space since last year is on track to smash into the moon at high speed early Wednesday (August 5) morning. The school-bus-size object is the second stage of a SpaceX Falcon 9 rocket that had launched a lunar lander from Firefly Aerospace toward the moon in January 2025.
Weighing four metric tons (4,000 kg), the rocket body is due to hit the moon around 2:35 a.m. ET (0635 GMT), hitting its surface at 5,400 miles per hour (8,690 kph). The space junk will kick up a plume of lunar dust that will likely be illuminated by sunlight but difficult to spot with the naked eye from Earth.
The impact is unintentional, SpaceX said. The rocket piece is expected to hit Einstein Crater on the moon's western limb, which is often difficult to see from Earth.
Such stages typically fall back into Earth's atmosphere and burn up or plunge into the ocean after boosting the rocket's payload to a precise spot in orbit. But because the January lunar lander mission required more thrust than missions closer to Earth, the rocket's second stage remained in space, floating aimlessly among thousands of other pieces of space junk that active satellites must steer clear of.
It was not until earlier this year that astronomers determined that the rocket stage, which had dumped its remaining fuel and cannot be controlled, was on an orbital trajectory ending at the moon.
"What has happened is essentially a mixture of solar activity and gravity forces have put it on a path toward the moon," Julianna Scheiman, SpaceX director of NASA science and Dragon programs, told reporters on Monday.
Space junk impacts on the moon are rare. A Chinese rocket stage crashed into the moon in March 2022 after completing a lunar test mission. In 2009, NASA intentionally crashed a rocket stage into the moon to study the plume of lunar material kicked up by the impact.
NASA and SpaceX are discussing ways to prevent future lunar impacts, Scheiman said. The U.S. space agency plans to build a lunar base and send routine astronaut missions to the lunar surface beginning later this decade under its multibillion-dollar Artemis program. It would not want errant pieces of space junk impacting those assets.
