Mystery spheres on beach are likely space debris that fell back to Earth

Six metallic spheres found at Forrest Beach in Queensland, Australia, were likely space debris, the Australian Space Agency said. (Queensland Fire Department via CNN Newsource)

Six mysterious metal spheres that washed ashore last weekend at Forrest Beach in northern Queensland, Australia, are “suspected space debris,” the Australian Space Agency announced Monday on social media.

Informally dubbed “space balls,” the large objects are likely pressure vessels — heavy-duty containers of pressurized gases and liquids — from a rocket that re-entered Earth’s atmosphere, according to the agency. The spheres were roughly twice the size of a basketball, local residents reported.

Although the space agency initially discouraged the public from going near the spheres, Queensland emergency responders have since removed the objects and determined them to be safe, the ASA confirmed. Agency officials say that further debris may be found.

“Never touch, move or recover suspected space debris and assume it to be hazardous until advised otherwise. Move away and contact emergency services,” wrote an ASA spokesperson in an email to CNN.

The agency is currently working with international authorities to determine which vehicle the space balls fell from, and which nation conducted a launch.

The problem of space junk

Space junk can take a variety of forms, such as dead satellites, empty fuel tanks or microscopic paint flecks. As space innovation and exploration has expanded in recent decades, researchers have been studying the motion of spacecraft to mitigate satellite collisions and possible hazards on Earth.

Still, the debris has become an increasing issue. The amount of space debris the military was tracking from 2013 to 2024 increased by more than 104 per cent, from 23,000 pieces of debris to 47,000, according to reports from the United States Space Force. As most objects are believed to be too small to track, ranging in size from one millimetre to 10 centimetres, NASA estimates that millions of debris are in low Earth orbit.

It isn’t common for space junk to fall to Earth, but it does happen from time to time.

In March, a NASA spacecraft re-entered Earth’s atmosphere, though it was expected that most or all of the probe burned up in the process.

Recent years have also seen a number of space debris incidents, including in 2023, when a mysterious 10-foot (three-metre) cylinder washed ashore at Green Head, a coastal town north of Perth, Australia.

And in 2024, debris from the International Space Station that had been expected to burn up as it fell to Earth struck a Florida home.

While no documented deaths have occurred due to space debris, there have been reports of injuries, noted John Crassidis, professor of mechanical and aerospace engineering at New York’s University at Buffalo.

A six-year-old boy in China’s Shaanxi Province was hit by a rocket fragment in 2002. A few years prior, Lottie Williams was struck by a piece of space debris in a suburb of Tulsa County, Oklahoma, becoming the first person known to have been hit, according to Guiness World Records.

Experts emphasize that mitigating these risks requires preparation to prevent collisions between satellites and other spacecraft.

“One of the things that aerospace has done over time is looked at some of these re-entered objects to try to understand what conditions are. How do we improve our models?” said Marlon Sorge, executive director of The Aerospace Corporation’s Center for Orbital and Reentry Debris Studies.

Most space junk orbits Earth at dangerous speeds, with some pieces reaching up to 18,000 miles per hour (nearly 29,000 kilometres per hour). That’s nearly seven times faster than a speeding bullet, according to NASA.

The latest report from the European Space Agency estimates that more than 650 collisions between defunct objects have resulted in fragmentation since 1961 when the first report of an in-orbit satellite fragmentation was documented.

But the odds of being hit by space debris that falls to Earth remain low — less than one in one trillion — according to The Aerospace Corporation.

“As we progress through this the space age, we’re getting better and better at understanding how to deal with these kinds of issues,” said Greg Henning, debris and disposal analyst at The Aerospace Corporation.

In recent years, space tech companies have made an effort to control the problem. SpaceX, for example, has developed reusable rockets, and Astroscale, an on-orbit servicing company, is creating a robotic space arm that can catch dead satellites.

“There’s much more awareness of this whole re-entry risk problem,” Sorge said. “A lot of operators will intentionally design their satellites to try to make sure that nothing dangerous or very little that’s dangerous survives.”

“We need to make sure that we implement guidelines, mitigation approaches to prevent this stuff from becoming a problem,” Sorge added.