T
he spent upper stage of SpaceX Falcon 9 was adrift in the space for 18 months, moving without any guidance mechanism, drifting under the effect of gravitational forces and sun radiation pressure for quite a long time.
In the early morning of Wednesday, August 5, the spent upper stage collided with the surface of the Moon with incredible speed of about 5,400 miles per hour, near the crater Einstein.
It all started on January 15, 2025, when a SpaceX Falcon 9 rocket blasted off from Kennedy Space Center carrying the two private lunar landers: the Blue Ghost of the Firefly Aerospace company and the Resilience of the Japanese company ispace. While the reusable first stage booster returned back to Earth normally, the Falcon's second stage continued to move with these private lunar landers towards the Moon.
One month and a half later, Blue Ghost made a soft landing on the lunar surface becoming the first privately owned spacecraft to make a soft landing on the lunar surface. As to the resilience, it unfortunately failed and made a crash landing.
After delivering two lunar landers to their targets, the work of upper stage was supposed to finish, and it was supposed to eventually leave the Earth system. Normally, the disposal of such stages is made through burning these stages in the Earth's atmosphere, but in case of the lunar missions, some other procedure is needed.
That particular Falcon 9 second stage collided with the Moon.
Independent observers were among the first to identify the threat. After analyzing public data sets used to track satellites, observers determined months ago that the approximately 8,800-pound upper stage would inevitably collide with the moon after being launched into space. NASA’s Center for Near-Earth Object Studies, which works as part of the Jet Propulsion Laboratory responsible for keeping track of potentially threatening asteroids, confirmed the impact course. Scientists managed to pinpoint within half a second the moment of collision and narrowed down the point of contact to 300 yards in advance. However, there are unknown variables—the outgassing fueled by the remains of the rockets' fuel, among other unpredictable elements, can cause slight deviations from the calculations.
This place is located on the Moon’s western side, near two craters named Einstein and Bell in a region heavily affected by asteroid activity.
Travelling faster than 5,400 miles per hour, the upper stage impacted with the energy of about three tons of TNT, thus creating a crater about 60-90 feet in diameter and several feet deep.
Humans have been placing devices on the Moon ever since the year 1959 when Luna 2 – the first space probe in the world – touched its surface, marking it as the first place outside of Earth that got visited by a human-made device. Since then, nearly seventy devices have landed or crashed onto the Moon's surface; those include devices with astronauts who went there during the Apollo era. Controlled impacts on the lunar soil have a fairly long history from the days of the early missions: during the period of the Apollo 13 to Apollo 17 missions, NASA has been crashing their spent Saturn V third stages onto the surface of the Moon in order to trigger the earthquakes which would be recorded by the equipment left there previously by the earlier astronauts.
The same way NASA performed a crash in the year 2009 when NASA crashed a Centaur upper stage in the neighborhood of the Moon's south pole searching for evidence of presence of ice.
What distinguishes the current event from other similar events is the fact that it happened without any planning and was uncontrolled.
At the same time, however, the specialists consider this event as an unusual but valuable and cheap experiment as scientists know exactly its mass and velocity of the device, its components.
Carl Schmidt – planetary scientist from Boston University explained for reporters that there were many instruments observing this impact including Very Large Telescope in Chile observing sodium and lithium atmosphere plume.
Given the fact that the crash occurred on the sunlit part of the Moon, no one really expects to see the actual impact.
It would have been almost invisible against the bright face of our natural satellite, but NASA's Lunar Reconnaissance Orbiter has captured craters from other impact events, so this time too, it is expected that it will produce images before-and-after this event, though it will take about one or two weeks for it. Other orbiters such as Danuri from South Korea, and Chandrayaan-2 from India can also provide their observation to accurately locate the impact spot.
NASA has treated this event more like an opportunity rather than a problem because its scientists aim to learn more about object tracking and impact physics using the information acquired from this incident, and it comes in handy as the agency will start implementing its Artemis program very soon in which a sustainable human presence on the Moon needs to be ensured.
Officials have stressed that there is absolutely no harm caused to the Earth due to this crash. To give some perspective into it, NASA says that there is one meteoroid carrying similar energy that strikes the Moon every six days; that means the Moon gets impacted without the need for used rocket stages to be sent to it.
