A spent SpaceX Falcon 9 upper stage was expected to strike the Moon near Einstein crater at about 06:35 UTC on Wednesday, August 5, giving scientists a rare chance to study a precisely forecast artificial impact. Researchers said the event should have occurred on sunlit terrain near the lunar limb, but confirmation will depend on observations and later images of a fresh crater.
The object, catalogued as 2025-010D, came from the January 15, 2025 launch that carried Firefly Aerospace's Blue Ghost and the Japanese company ispace's Resilience lunar landers. After releasing the spacecraft, the upper stage remained in a distant orbit influenced by the gravity of Earth, the Moon and the Sun until tracking showed that its path would intersect the lunar surface.
A research team led by planetary scientist Benjamin Fernando forecast an impact at roughly 06:35 UTC near Einstein crater and encouraged professional and amateur observers to record a brief flash or ejecta plume. The team stressed that the brightness was uncertain. Axios reported on Tuesday that NASA planned to photograph the site from lunar orbit, which could provide the clearest confirmation and measurements.
Separate physical observations independently linked the object to the 2025 mission. A team led by Theodore Kareta used visible and near-infrared spectroscopy to identify absorption features consistent with spacecraft thermal-control materials, while light curves indicated an elongated body rotating about once every seven minutes. That group estimated an impact speed near 2.4 kilometres per second and a crater around 40 metres wide.
Another modelling study led by William Jo used an estimated mass of about 3,900 kilograms and a speed of 2.43 kilometres per second to examine the possible debris plume. Published estimates for crater size differ, with another observing plan suggesting about 27 metres, because the stage's exact mass, structure, angle and the properties of the lunar soil are not fully known. No danger to Earth was expected.
Scientists say the value of the event lies in comparing a known incoming object with the flash, plume and crater it produces. The results could improve methods for locating future lunar impacts, interpreting natural craters and assessing debris hazards as activity grows between Earth and the Moon. Researchers must now compare ground and spacecraft observations with before-and-after orbital images before declaring what was detected.
Comments