After launch more than 50 years ago, a Soviet spacecraft called Kosmos 482 is expected to crash back onto Earth.
The spacecraft was originally intended to land on Venus, but started to fall apart in low Earth orbit and never made it past there.
After decades in orbit, it is starting to hurdle back towards the ground.
Tracking the spacecraft as it hurdles back towards Earth is difficult, according to Asia Pacific Aerospace Consultants' orbital expert, Bill Barrett.
"It's very hard just to predict when something like this is going to come back … [it's] one of the hardest things in orbital mechanics," he told ABC News.
Kosmos 482 is predicted to land at around 3:54 pm (AEST) on Saturday, 10 May. It is currently above Earth in an orbit of 140 kilometres at its lowest and 260 kilometres at its highest.
It is impossible to determine exactly where it will land. It could land anywhere from South America's southern tip to parts of Canada and Russia.
University of Colorado Boulder Laboratory for Atmospheric and Space Physics research scientist, Marcin Pilinski said the chances of the spacecraft landing in a populated area are low.
“It’s an infinitesimally small number,” Pilinski said.
“It will very likely land in the ocean.”
Not much is known about the Kosmos 482 mission, due to Cold War secrecy, other than it was intended to land on Venus. It was unclear what caused the mission failure but not long after the launch, three pieces of the spacecraft were found in New Zealand.