A roughly five-ton piece of a SpaceX rocket that sent two lunar landers to the moon is about to join them, but not on purpose.
On Aug. 5 at around 2:34 a.m. ET, the upper stage of a discarded Falcon 9 rocket will collide with the moon at 5,400 miles per hour near the crater Einstein on the western lunar limb, according to Bill Gray, who runs Project Pluto and develops software for tracking astronomical objects.
Gray was the first to calculate that the object would hit the moon and has been tracking it since. He also co-authored a study on the impact with an international team of researchers who recently made their work available on the open-access preprint arXiv server. The paper has not been peer-reviewed.
“We expect that to vaporize the booster, create a flash of light, probably a plume of ejecta — dust, regolith, other stuff mixed into it — and of course excavate a fresh crater on the lunar surface,” Benjamin Fernando, a postdoctoral researcher at Los Alamos National Laboratory in New Mexico and the lead author of the study, told ABC News.
Fernando said the impact event offers scientists a unique opportunity. He said we often see meteoroids striking the lunar surface, but it’s often difficult to know the mass and speed of the objects. Because the researchers know those two variables for the upper stage, they can use the impact as a “calibration event to test all of the techniques that we use for studying natural impacts, which we don’t know are going to happen in advance, unlike this event,” according to Fernando.
The researchers will also use the impact to better understand the makeup of the moon. When the upper stage hits, it will send up a plume that scientists are hoping to measure.
“If we can measure the composition of that, that tells us something about the composition of that part of the moon,” Fernando said.
With NASA planning to return astronauts to the surface of the moon as early as 2028 and eventually build a permanent moon base, Fernando said the impact is also an opportunity to study the risks of lunar impacts on people and equipment.
“These sorts of things are going to happen more and more often. And as we have more astronauts on the lunar surface, more lunar infrastructure habitats, for example, we need to understand how much of a risk these impact events actually pose,” said Fernando.
He went on, “This is an ideal way of studying both the direct risks, the risk of being hit by debris or being blinded by a flash of light, but also the indirect risk, the risk of being hit by a cloud of ejected material and having that disrupt or interfere with spacecraft functions in lunar orbit as well.”
On Jan. 15, 2025, SpaceX launched a Falcon 9 rocket carrying Firefly Aerospace’s Blue Ghost 1 lunar lander and ispace’s Resilience lander toward the lunar surface. Blue Ghost successfully landed on the moon on March 2, 2025. Resilience, on the other hand, crashed on the lunar surface after communications were lost with the vehicle 90 seconds before landing.
The Blue Ghost moon lander is photographed at Firefly Aerospace headquarters, Dec. 3, 2024 in Cedar Park.
Raquel Natalicchio/Houston Chronicle via Getty Images
During the mission, the upper stage of the Falcon 9 rocket “was abandoned in a moon-crossing high-Earth orbit,” according to researchers. And now it’s on a collision course for the lunar surface.
“I don’t think we know from SpaceX exactly to what degree they were in the know that this was going to happen. Certainly, the fact that it was used to deliver hardware to the moon meant that it was probably left in an orbit where there was a possibility of this happening. Whether they knew that it was going to happen and didn’t say anything, or they simply hadn’t run the calculation, I couldn’t tell you,” said Fernando.
The flash will be far too faint for the naked eye, so you’ll need a telescope, and even then the odds are poor. No impact flash has ever been recorded on a sunlit part of the moon, which is exactly where this one will land. Still, Fernando said a small amateur telescope is worth pointing at it, and the research team is encouraging anyone willing to get up early or stay up late to look and report what they see.
“It might be that they see a flash of light. It might be that they see the plume of debris. Obviously, the bigger the telescope, the better the conditions, the more likely you are to see something,” Fernando said.
“But because these events are so rare, we don’t have a good expectation of exactly what we’re going to see, which is exactly one of the reasons why we’re asking people to take a look,” he added.
Leave a Reply