Upper stage impacting the moon on 2026 August 5

List of changes to this page (most recent 2026 July 17) Copyright info On 2026 August 5, within a few minutes of 06:35 UTC, an upper stage (section) of a rocket used for a lunar mission will hit the moon. This may be of some (probably minor) scientific interest, and we may learn some things from it. It doesn't present any danger to anyone, though it does highlight a certain carelessness about how leftover space hardware (space junk) is disposed of. This is the second time I've identified a piece of junk as being about to hit the moon. That event got considerably more attention than I'd expected, including from non-astronomers. I'm hoping the following will answer most of the questions people are apt to have about this new event. What is this object? Who observed this object? How was the impact predicted? Where and when will it hit the moon? What else do we know about the object? How fast will it be going when it hits the moon? Will the impact be visible from earth? Might we see the ejecta plume? Where is the object now? Will we get pictures of the resulting crater? Why worry about this? Should we worry about space junk in general? Are there ways to avoid lunar impacts? News articles about this impact Contact info What is this object? This is the upper stage of a Falcon 9 rocket. The Falcon 9 is SpaceX's workhorse rocket. These rockets have two stages. The first, larger stage gets the payload (and upper stage) most of the way to orbit, and then comes back to earth and lands on a barge, and can be re-used. The upper, smaller stage goes into orbit and can't be re-used. As you can see in the above image, it's still quite a large object, roughly the height of a five-story building. Over 600 Falcon 9 rockets have been launched. Most of the upper stages are either in orbits close to the earth or have already re-entered the earth's atmosphere. A few are orbiting the sun. The object that will be hitting the moon has been orbiting the earth for a little over a year. The object doesn't have a name, just an official catalog designation of 2025-010D. That tells you that it was on the tenth rocket launched into orbit in 2025, on January 15 of that year, and was the fourth bit of hardware to be tracked from that launch. The purpose of the mission was to launch the Blue Ghost and Hakuto-R landers to the moon. Those were designated 2025-010A and 2025-010B. They were held together by 2025-010C, a "payload canister". 2025-010D was the Falcon 9 upper stage, a rocket that propelled everything else from a low orbit around the earth into an orbit that could reach the moon. Once it had done that, all four objects separated from each other. Over the following weeks and months, all four pieces were tracked by the telescopes of asteroid surveys and amateur astronomers. Blue Ghost landed on the moon on 2025 March 2. Hakuto-R took a much more circuitous route to save on fuel, and attempted to land on 2025 June 5. Unfortunately, contact with it was lost about 90 seconds before landing, and it crashed. The payload canister, 2025-010C, kept orbiting the earth and re-entered the earth's atmosphere at 12:06 UTC on 2025 March 15, near the border between Argentina and Chile. I don't know if anybody actually saw it. If they did, it would have looked like a fairly bright meteor. The upper stage, 2025-010D, also kept orbiting the earth, but was a bit higher and didn't re-enter. It's had a few close passes by the moon and earth, but nothing that was close enough to look like a possible impact. The asteroid surveys observed it whenever it wasn't too close to the sun or moon to see. As of 2026 February 26, we had accumulated 1053 observations of it. Who observed this object? This object has spent almost all of its time at distances similar to that of the moon. Generally speaking, such objects are very poorly tracked. The US military mostly tracks objects using radar. That does a superb job of tracking low-orbiting junk; they've tracked gloves and tool bags that astronauts have lost over the years. But the moon, and objects like 2025-010D, are about 400 times further away; the radar signals are about 25.6 billion times fainter. (If an object is 400 times further away, it receives 1/400 squared, or 1/160000, as much radar energy. And of that, only 1/160000 as much is returned to earth.) Basically, the radar works well for "close" stuff, and the telescopes work better for more distant objects. However, these objects are entirely observable by the asteroid surveys, and even by amateur astronomers with suitably advanced gear and techniques. You can click here to see observational data gathered by amateur observers and the resulting orbit and impact prediction. (This is in a somewhat opaque form that is quite familiar to asteroid observers.) This includes observations from five observatories in Mississippi, Utah, Beijing, and England. The asteroid surveys have gotten even more data on this object. They would actually prefer not to observe space junk. Their job is to find and track rocks that might hit the earth ("planetary defense"). Time spent observing junk is time not spent finding rocks. But both the rocks and the high-altitude space junk are slowly moving points of light in their images; they aren't easy to distinguish. So the asteroid surveys find this sort of junk whether they want to or not. How was the impact predicted? For some time, I've provided some software tools astronomers can use to identify satellites in their data. I use the US military's publicly available satellite data for many objects, and compute orbits for high-orbiting objects the military doesn't track. This object falls squarely in the latter category. In September 2025, my software for computing orbits analyzed the observations and projected an impact with the moon on 2026 August 5. While this looked like a pretty solid prediction, I couldn't be totally sure of it at the time. The motion of space junk is mostly quite predictable; it simply moves under the influence of the gravity of the earth, moon, sun, and planets. We know those with immense precision. If those were the only factors involved, I could probably tell you where and when this object would hit the moon to within a few meters and a fraction of a second. The problem is that space junk in general, and 2025-010D in particular, is also pushed around by sunlight ("solar radiation pressure"). This is an extremely gentle force, but over months, it can really build up. And it's not entirely predictable. As an object tumbles, it may catch more or less sunlight, and may reflect some of it sideways. So sunlight is mostly pushing the object away from the sun, but there's a slight bit of pushing in other directions as well. With enough data, we can actually figure out where the forces are pushing an object. But they do change a little over time in ways that aren't perfectly predictable. So I can be sure it will impact near the time and place I've predicted, but those varying forces mean that the actual impact will be at least a little off from that time and place. That's the largest source of uncertainty in all this, and there's no way to correct for it; we just have to wait and see what actually happens. (But come August, we'll have a quite precise idea of where it will hit.) Where and when will it hit the moon? With the data I've seen as of 2026 July 17, I'm computing an impact on 2026 August 5 at 06:34:32.9 UTC (Universal Time), probably plus or minus a few seconds. Locally, that will be : 2:34:32.9 AM (US) Eastern Daylight Time; 1:34:32.9 AM (US) Central Daylight Time; 12:34:32.9 AM (US) Mountain Daylight Time; 11:34:32.9 PM (US) Pacific Daylight Time on August 4; 7:34:32.9 AM Western European Summer Time; 8:34:32.9 AM Central European Summer Time; 9:34:32.9 AM Eastern European Summer Time; 4:34:32.9 PM Australia Eastern Standard Time; 4:04:32.9 PM Australia Central Standard Time; 2:34:32.9 PM Australia Western Standard Time The impact point will be at lunar latitude 19.455 N, longitude 266.406 E = 93.594 W. The first image shows how it'll look from the earth, with the impact at the blue circle-and-cross symbol. Somewhere close to that place and time, anyway; as described above, some parts of the motion of this object aren't entirely predictable. It will be close to the edge ("limb") of the moon as seen from earth, on the sunlit part. The moon will be a little more than half illuminated at the time. The second image is a closer look from directly above the impact point. The impact will be close to the crater Einstein, in a heavily cratered part of the lunar surface. In theory, the time is good to about half a second, and the position to about 0.01 degrees (which is about a third of a kilometer or around 300 yards). The problem is that the theory doesn't account very well for those unpredictable bits; I'm not really trusting the above to better than a few seconds and a few kilometers. However, we will have a more exact answer a bit before it hits. In the days before impact, it will be quite well placed for telescopic observations (it won't be in daylight, or too far away, or poorly illuminated by the sun). The reason we'd like as precise an impact point as possible is to help in figuring out where to find and image the resulting crater. I expect we'll be able to tell the LRO folks exactly where to look in their images for the crater. What else do we know about the object? Because we know it's a Falcon 9 upper stage, we have a good idea of its dimensions, and know that has a mass of about 4900 kg. (The mass was, and remains, something of an unknown for the Chang'e-5 T1 upper stage that hit the moon. We were a little surprised to see that it made a double crater; the current guess is that there was a heavy motor at one end plus a heavy payload near the top of the upper stage. But we don't really know, and the China National Space Agency isn't saying... in fact, as far as I know, they've yet to say that it was their bit of