The latest "educated forecast" for where a part of an out-of-control rocket will land this weekend has been revised, and it's New Zealand's North Island.

But don't worry: most of the rocket's debris will be burned up on re-entry and is unlikely to cause any damage, according to China's foreign ministry. Experts added that pinpointing the re-entry site would be impossible, and debris would most likely end up in the ocean.

The Aerospace Corporation said the latest forecast for the re-entry of the 18-tonne Long March 5B rocket body by its Centre for Orbital Reentry and Debris Studies (CORDS) was for eight hours either side of 0419 GMT on Sunday in a tweet sent on Friday evening in the US (8 am-midnight Sunday NZ time).

CORDS' most recent "educated forecast" showed a re-entry site near the North Island as a probable candidate, but it also noted that re-entry could occur anywhere along paths that span vast swaths of the globe.

Normally, first-stage rockets re-enter the atmosphere shortly after lift-off, usually over water, and do not enter orbit, as this one did.

New Zealand is one of a number of worldwide places in the course of the rocket's trajectory, according to an astrophysicist, though the debris is more likely to fall into the ocean.

Given that the ocean covers 70% of the earth, astrophysicist Jonathan McDowell of Harvard University believes potentially hazardous debris would possibly avoid incineration and fall into the sea.

McDowell, a member of the Harvard-Smithsonian Centre for Astrophysics, predicted that the rocket's main stage core would shatter into a shower of debris similar to that of a small plane crash, resulting in a 160-kilometer-long trail of debris.

According to McDowell, the debris trail could fall as far north as New York, Madrid, or Beijing, or as far south as southern Chile and Wellington, New Zealand, or anywhere in between, based on its current orbit.

The stage's "thin-skinned" aluminum-alloy exterior, according to the Chinese Communist Party's Global Times, would quickly burn up in the atmosphere, posing an extremely remote danger to citizens.

According to business insiders, the situation is "not worth panicking over."

The newspaper quoted Wang Yanan, chief editor of Aerospace Knowledge magazine, as saying, "Much of the debris will burn up during re-entry... leaving only a very small amount that could fall to the ground, which will theoretically land on areas away from human activities or in the ocean."

The Long March 5B rocket core "cannot be pinpointed until within hours of its re-entry," according to the US Defense Department.

"Given the scale of the object, there would inevitably be large parts left over," said Florent Delefie, an astronomer at the Paris-PSL Observatory. "The odds of debris impacting on an occupied zone are extremely remote, perhaps one in a million," he said.