Several large metallic balls washed up on Forrest Beach in North Queensland, Australia, this week, prompting Queensland Fire and Rescue to warn the public to stay away from the potentially hazardous objects. The Australian Space Agency has since concluded that the mysterious spheres are almost certainly space debris, adding a real-world example to growing concerns about the volume of junk returning to Earth as global launch activity increases.

According to the agency, the recovered objects appear to be pressure vessels from a space launch vehicle, and their location and characteristics are consistent with debris from a foreign rocket body that recently re-entered the atmosphere from orbit. Officials say they have identified a likely source and are working with international counterparts to determine which country the debris came from. Authorities have advised anyone who encounters space junk not to handle it or take it home.