China's first prototype space station, Tiangong-1, is expected to re-enter the atmosphere early next year, as its operational life comes to an end.
According to the European Space Agency (ESA) on Monday (Nov 6), the 8.5-tonne space station, which is unmanned, will make an "uncontrolled re-entry" to Earth between January and March next year.
Most of the craft should burn up in the atmosphere, but parts of the debris could land on Earth, said experts.
The ESA predicted that fragments could fall over any spot within 43ºN and 43ºS, latitudes which encompass major Asian cities such as Beijing, Tokyo, Bangkok, Singapore and New Delhi.
The Middle East, the African continent, parts of Europe such as Spain and Italy as well as American cities like San Francisco, New York and Miami are also within the latitude range.
The space agency explained that it is not possible to provide more precise landing locations.
“The date, time and geographic footprint of the reentry can only be predicted with large uncertainties. Even shortly before reentry, only a very large time and geographical window can be estimated," said ESA.
"Owing to the space station's mass and construction materials, there is a possibility that some portions of it will survive and reach the surface."
However, the ESA also noted that in the history of spaceflight, there have been no confirmed casualties caused by falling space debris.
Tiangong-1, which means "heavenly palace" in Chinese, is 12m long with a diameter of 3.3m and a launch mass of 8,506kg. It is now at about 300km altitude in orbit.
It was sent to help China master key rendezvous and docking technologies as a prelude to build a large space station.
"It has been unoccupied since 2013 and there has been no contact with it since 2016," the ESA said.
The agency added that it will host a test campaign to monitor the re-entry of the space station. Experts will pool their predictions of the time window, as well as their respective tracking datasets obtained from radar and other sources.
"The aim is to cross-verify, cross-analyse and improve the prediction accuracy for all members," the agency said.