A retired Falcon 9 rocket crashes into the moon. The collision will bring a rare opportunity for scientists.

A decommissioned Falcon 9 rocket stage will crash into the Moon’s surface on August 5, offering scientists a rare opportunity to study lunar impacts and refine their models of such events. The impact is expected to create a new crater, produce a brief flash of light, and generate a plume of dust several kilometers high. The object, designated 2025-010D, was launched in January aboard a mission carrying landers from companies Firefly and ispace. After completing its task, the upper stage lacked enough fuel to return to Earth or venture further into deep space, leaving it in a high orbit that intersects with the Moon's path. The rocket stage, measuring twelve meters in length, four meters in width, and weighing approximately four thousand kilograms, is projected to strike near the Einstein crater on the side of the Moon visible from Earth around 8:35 Central European Time. It will hit the surface at nearly nine thousand kilometers per hour at an angle of thirty-four degrees. Scientists anticipate the structure, which is mostly hollow metal, will crumble upon impact, excavating a large amount of material from the lunar surface. Models predict the impact will form a crater ranging from twenty to thirty meters wide and about five meters deep. Researchers have not ruled out the possibility of a double crater, similar to one created by China’s Chang’e 5 rocket in 2022 on the far side of the Moon. Simulations using the HOSS software suggest the collision will eject over a million kilograms of lunar dust and rock, almost twice the mass of the rocket itself. Most of this material will fall back onto the surface within seconds, creating smaller secondary craters. Smaller particles could rise several kilometers high and remain suspended in the vacuum of space for up to ten minutes. This ejected debris represents the best target for astronomers. Light reflecting off these tiny particles might allow observation from Earth, even though the Moon will be 56 percent illuminated at the time. However, the crater itself will be too small to see directly through telescopes on Earth. Scientists plan to use NASA’s Lunar Reconnaissance Orbiter and South Korea’s Pathfinder Lunar Orbiter to photograph the surface before and after the impact. The latter satellite will fly just a few kilometers away from the rocket two minutes prior to the collision. Observing the flash of light presents the greatest challenge. This brief burst, lasting less than a second, has yet to be detected on the sunlit side of the Moon by scientists, whether from natural or artificial sources. The intensity of the light will depend heavily on whether the rocket hits loose dust or solid rock. Despite these uncertainties, artificial impacts on the Moon hold significant scientific value. With precise knowledge of the rocket’s properties, researchers can improve their impact models. Additionally, the event highlights the growing issue of space debris in the region between Earth and the Moon. As human presence on the Moon increases, tracking these objects becomes crucial for ensuring the safety of future astronauts and lunar infrastructure.