Tiangong-1: Watch the skies on Monday if you want to see it burn

Out-of-control Chinese space station Tiangong-1 might not re-enter the atmosphere until Monday afternoon (NZ time) astronomers now say.

Previous estimates of its descent had suggested Sunday morning was most likely. New figures crunched by the European Space Agency (ESA) now put the likely descent sometime on Monday.

"The team now are forecasting a window centred around 23:25 UTC on 1 April (01:25 CEST 2 April), and running from the afternoon of 1 April to the early morning on 2 April," the ESA said in a blog post.

That's 11:25pm on Sunday night at the earliest.

"This remains highly variable," said the ESA.

The difficulty in predicting when Tiangong-1 will enter the atmosphere and burn up is down to its odd shape, chaotic spin and the fluctuating density of the Earth's upper atmosphere.

"A high-speed stream of particles from the sun, which was expected to reach Earth and influence our planet's geomagnetic field, did, in fact, not have any effect," said the ESA.

"This means that the density of the upper atmosphere, through which Tiangong-1 is moving, did not increase as predicted."

If it had, the space station would have been dragged down closer to the original estimated entry time.

"Calmer space weather around Earth and its atmosphere is now expected in the coming days."

The station could fall anywhere between Christchurch in the south and London in the north.

"In the history of spaceflight, no casualties due to falling space debris have ever been confirmed," the ESA said last month.

Control of Tiangong-1 was lost two years ago, and its orbit had been decaying ever since.