Earlier this year, a Chinese rocket booster crashed into the lunar surface in a rare example of a piece of human-made debris colliding with the moon. Now, the site of this crash has been imaged by NASA’s Lunar Reconnaissance Orbiter, showing the crater created by the impact.
The impactor was originally thought to be a piece of SpaceX hardware, but further investigation showed it was actually the booster from a Long March 3C rocket. The rocket was launched as part of China’s Chang’e 5 mission in 2014, and although Chinese officials denied the booster belonged to them, evidence of the composition of the object suggested it was indeed part of a Chinese rocket.
This image, taken by the Lunar Reconnaissance Orbiter, has been enlarged by three times to show the impact location of the booster, near the Hertzsprung crater.
In an unexpected twist, the impact actually created two craters smushed together — one 18 meters across and the other 16 meters across. This unusual configuration hasn’t been seen in previous rocket impacts on the moon, such as those craters created when rocket upper stages were deliberately impacted into the moon during the Apollo missions.
“The double crater was unexpected and may indicate that the rocket body had large masses at each end,” NASA writes. “Typically a spent rocket has mass concentrated at the motor end; the rest of the rocket stage mainly consists of an empty fuel tank. Since the origin of the rocket body remains uncertain, the double nature of the crater may indicate its identity.”
Although the impact itself did little damage to the moon and was not widely considered to be a serious problem by scientists, it did point to a growing issue of space debris.
As junk like old satellites that no longer work or discarded rocket stages are left to float around in orbit around the Earth, it makes sending up new satellites more difficult and even threatens humans in space such as those on the International Space Station, which frequently has to maneuver to avoid debris.