A stray Falcon 9 rocket part is on course to slam into the moon in August.

The expected impact poses no immediate danger, experts say, but warn that it highlights a critical lack of rules for managing debris as lunar activity by the US, China and private companies ramps up.

Measuring 13.8 metres (45 feet) long and 3.7 metres wide, the SpaceX Falcon 9 rocket’s upper stage has been drifting through Earth-moon space since it launched a US commercial lander and a Japanese lander in January last year.

According to Bill Gray, a US-based independent astronomer and software developer, the stray part will hit Einstein crater on the moon’s near side at 2.43km per second (about 1.5 miles per second) around 2.44pm Beijing time on August 5.

The crash is likely to produce a flash of light and blast lunar rocks out of the crater at high speeds, Gray wrote on the website for his widely used Project Pluto software, which tracks near-Earth objects.

“Some of that shrapnel could, conceivably, go flying around and hit one of the Chinese lunar landers,” he wrote. “It’s very long odds against it; none of them are close to this spot. I don’t think it raises the usual risk level of being on the moon noticeably.”