The impact took place at 12:25 GMT on the far side of the Moon, according to astronomer Bill Gray, who first identified the upcoming collision.
Racing at more than 9,000 km / h, the cylindrical object should have dug a crater "10 to 20 meters in diameter", he told AFP.
Its trajectory had been calculated using observations made by telescopes on Earth.
"We had a lot of data on this object," said Bill Gray.
"Unless it was pulled out by an evil hand, it hit the moon this morning."
The identification of the rocket in question has been debated, as no one is officially responsible for listing and tracking space waste in deep space.
Mr. Gray, creator of software used by NASA-funded observation programs, monitors them so that they are not confused with asteroids, and thus unnecessarily studied.
After initially believing the remains were from a SpaceX rocket, he eventually announced it was a Chinese craft.
More specifically, the stage of a Long March rocket, which took off in 2014 for a mission named Chang'e 5-T1, as part of the country's lunar exploration program.
Beijing denied, assuring that the floor had "entered without danger into the Earth's atmosphere and had completely burned".
But according to Bill Gray, China confused two missions with similar names, and was actually talking about a rocket launched much later.
Be that as it may, the crater can only be observed by NASA's LRO (Lunar Reconnaissance Orbiter) probe, or the Indian Chandrayaan-2, both in orbit around this star.
The American space agency had confirmed at the end of January that it wanted to find the crater, but warned that the operation could take "weeks".
According to Bill Gray, the two probes can observe any lunar region once a month.
It is not unusual for rocket stages to be abandoned in the cosmos after propelling what they were launched to do.
But this is the first time that such an unintended collision with the Moon has been identified.
On the other hand, rocket stages have already been launched against the Moon for scientific purposes in the past, such as during the Apollo missions.
Studying the crater formed and the material stirred could thus advance selenology, the scientific study of the Moon.
© 2022 AFP