A Fascinating Collision on Our Natural Satellite
On August 5, 2026 at 06:35 UTC (3:35 a.m. Argentina time), the lunar surface witnessed an unusual and thrilling event for astronomy. The second stage of a SpaceX Falcon 9 Block 5 rocket impacted the Moon at a speed of 2.43 kilometers per second (8,700 km/h), creating a brand-new crater. Far from being a threat, this occurrence opens a unique door to scientific knowledge.
How Did a Rocket Get There?
This upper stage, identified as F9-427 (catalog number 2025-010D), had a mass of about 4 tons, measured 13.8 meters in length and 3.7 meters in diameter. It was launched on January 15, 2025 from Florida, carrying the lunar modules Blue Ghost M1 (from Firefly Aerospace) and Hakuto-R Resilience (from Japanese company ispace).
After deploying its payloads, the stage was left in a highly elliptical and unstable orbit of 176 x 362,529 kilometers. Over more than a year, gravitational perturbations from the Sun, Earth, and Moon, plus solar radiation pressure, altered its path. In September 2025, astronomer Bill Gray predicted the rocket would eventually crash into the Moon—a prediction that came true with remarkable precision.
The Stellar Role of the Danuri Probe
The impact occurred on the far side of the Moon, near the Einstein crater, at coordinates 19.476° north, 93.286° west. Since the Sun illuminated 56% of the Moon at that moment, the background was too bright to observe the flash from Earth. However, modern science provided us with unique images.
The South Korean probe Danuri (KPLO), operated by the Korea Aerospace Research Institute (KARI), conducted eight photographic sessions around the impact zone. The images showed a clear change: a new dark area and displaced material, evidence that the lunar regolith (the layer of dust and rocks covering the surface) was ejected by the collision's energy.
Additionally, the Very Large Telescope (VLT) at ESO in Chile captured the spectral signature of sodium (from the lunar soil) and lithium (from the rocket's metal alloy), confirming the impact beyond doubt.
What is Lunar Regolith?
It is the fine-grained material covering the Moon's surface, composed of dust, rock fragments, and minerals created by meteorite impacts over billions of years. Studying how it reacts to known impacts is key for future crewed missions.
A Brilliant Scientific Opportunity
For scientists, this event is a true astronomical gift. The Moon lacks an atmosphere, so craters remain intact for millions of years. By knowing the exact size, mass (4 tons), trajectory, and velocity of the object, researchers can correlate these data with the morphology of the generated crater. This information will be fundamental to improving models used to reconstruct impacts of meteorites and other space bodies throughout the Solar System's history.
Background and the Future of Space Debris
This is the ninth impact of a rocket upper stage on the Moon, and the third unintentional one. In the 20th century, NASA deliberately directed Saturn V rocket stages from Apollo missions to crash into the Moon to study its interior via seismic waves. More recently, in 2009, a Centaur rocket stage intentionally crashed into Cabeus crater to search for water.
With the increase in space missions to the Moon, especially by the United States and China, this event highlights the importance of properly managing space debris. Ensuring that rocket stages re-enter Earth's atmosphere will be a vital step to maintain the safety of future expeditions and keep our satellite clean.
Sources consulted:
TN, Eureka - Naukas (Daniel Marín), Infobae, La Mañana Neuquén, elDiarioAR.