Out-of-control Chinese rocket is falling back to Earth — but where?

The US Department of Defence has said it is tracking the Chinese Long March 5B-rocket that is out of control and set to re-enter Earth's atmosphere this weekend.

The core of the Chinese Long March 5B rocket carried the "core module" of the country's space station into low Earth orbit last week.

But after that mission was complete, the rocket appears to have fallen into an orbit that could see it plunge towards the Earth.

It is not clear how the 30-metre-tall rocket will fall, and where exactly it will land. Since 1990, nothing weighing more 10 tonnes have fallen back to Earth uncontrolled – and the Chinese rocket is thought to weigh about 10 tonnes.

The Chinese rocket is expected to enter Earth's atmosphere around May 8 and US Space Command is tracking the rocket's trajectory amid concerns about where its debris may make an impact, CNN reported.

"US Space Command is aware of and tracking the location of the Chinese Long March 5B in space, but its exact entry point into the Earth's atmosphere cannot be pinpointed until within hours of its re-entry, which is expected around May 8," Pentagon's US Space Command said in a statement.

The roughly 100-foot object is orbiting Earth every 90 minutes and zips past north of New York, Beijing and as far south as New Zealand, Fox News reported citing a space monitoring website.

The report said that despite the threat, it is most likely to splash in one of the world's oceans or in an isolated area. "I don't think people should take precautions. The risk that there will be some damage or that it would hit someone is pretty small -- not negligible, it could happen -- but the risk that it will hit you is incredibly tiny. And so I would not lose one second of sleep over this on a personal threat basis," Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, told CNN.

This comes a time when several experts in the West have raised concerns about the clandestine ambitions behind the construction of the Chinese station and triggering of a new 'space race'.

Last year, parts of one of the same rockets fell down to Earth, in a situation with marked similarities to this one.

Most of the pieces landed in the Atlantic Ocean. But pieces of debris were reported in Ivory Coast, and experts calculated that it had missed New York by minutes.