Astronomers intend to observe a stray piece of a SpaceX rocket as it hits the moon to better understand impact events.
By Claire Cameron edited by Jeanne Brner
The hidden side of the Moon seen by the crew of the Artemis II assignment. The Moon blocks all radio waves coming from Earth, so it’s an ideal place to gather them from the cosmos.
NASA
Astronomers are preparing for a unique moon sighting event: a misplaced piece of a EspaceX The Falcon 9 rocket is set to touch the lunar surface on August 5. The collision and its aftermath, which can be visible from Earth and space telescopes, present an opportunity for singular science.
In a new paper Published on the preprint server arXiv.org, 23 astronomers call on the scientific community to observe the event and note that it might be possible to record the impact as it occurs. The accident could reveal new information about what happens immediately after an impact on the lunar surface and offer insight into the dangers posed by wandering space debris on the Moon.
The curvy spacecraft was first spotted by amateur astronomer Bill Gray. Launched in January 2025, the Falcon 9 carried two landers to the moon: Blue Ghost from Firefly Aerospace and Hakuto-R from the Japanese company ispace. After delivery, the rocket’s upper stage was supposed to burn up upon re-entry into the Earth’s atmosphere. But like Scientific American reported in Maythis did not happen.
On supporting science journalism
If you enjoy this article, please consider supporting our award-winning journalism by subscribe. By purchasing a subscription, you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Instead, it entered orbit around Earth at a distance similar to that of the Moon. Objects like this are difficult to track from our planet, Gray noted in a recent blog post. The rocket fragment’s movement is difficult to predict, Gray wrote, because it is under the influence of both gravity and the pressure of solar radiation, a subtle force that affects its direction of movement in ways that are difficult to predict.
Gray predicted that the 10,800-pound space debris would hit the Moon around 2:34 a.m. EDT on Aug. 5 and crash near the edge of the Moon as seen from Earth, near Einstein Crater. When it crashes into the Moon, it will be traveling at a speed of 5,400 miles per hour, several times the speed of sound, and with an energy similar to three tons of TNT, according to Gray.
In the new preprint, the astronomers (including Gray) write that detecting the impact flash will likely be difficult due to the likely location of the accident on the moon’s sunny hemisphere. Indeed, no artificial or natural impact flash has ever been observed on the illuminated surface of the Moon, they write.
“The fact that the impact is Really close to the limb may actually prove to be an advantage. “Rocks ejected by the impact may form a ‘plume’ that will be visible against the dark background once they leave the moon,” Gray wrote in his blog, adding that what is visible will become more apparent as the impact approaches.
“Maybe we’ll see the flash,” he wrote. “Maybe we’ll see rocks ejected from the crater. Maybe we’ll even see both.”
The crater will likely be more visible using space observatories, and NASA’s Lunar Reconnaissance Orbiter is expected to image the impact site before and after the collision, according to the newspaper. South Korea’s Pathfinder Lunar Orbiter will also attempt to observe the rocket fragment as it impacts the lunar surface and study the aftermath.
In the article, the authors encourage anyone who can observe the impact to try it and emphasize guides to help amateurs.
“The next impact of the Falcon 9 upper stage on the Moon, on August 5, 2026, presents an ideal opportunity for Americas observers and space assets to study a significant lunar impact in real time,” they write.
The event is timely, the paper says: NASA and other space agencies are stepping up their lunar ambitions, with plans for human missions to the Moon and, eventually, permanent staff. lunar bases. Tracking space debris in lunar orbit will be crucial to these efforts, the authors note.
It’s time to defend science
If you enjoyed this article, I would like to ask for your support. Scientific American has been defending science and industry for 180 years, and we are currently experiencing perhaps the most critical moment in these two centuries of history.
I was a Scientific American subscriber since the age of 12, and it helped shape the way I see the world. SciAm always educates and delights me, and inspires a sense of respect for our vast and magnificent universe. I hope this is the case for you too.
If you subscribe to Scientific Americanyou help ensure our coverage centers on meaningful research and discoveries; that we have the resources to account for decisions that threaten laboratories across the United States; and that we support budding and working scientists at a time when the value of science itself too often goes unrecognized.
In exchange, you receive essential information, captivating podcastsbrilliant infographics, newsletters not to be missedunmissable videos, stimulating gamesand the best writings and reports from the scientific world. You can even give someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.
