Scientists warn the manmade junk, officially designated WT1190F but nicknamed WTF, will strike Earth on November 13.

The WT1190F is predicted to land in the seas off Sri Lanka's Southern coast.

Much of the hollow object, which may be a spent rocket stage or panelling shed by a recent Moon mission, should burn up in the atmosphere.

But any remnants could dive bomb from the skies – and an international team of astronomers are using it to test emergency plans for dealing with potentially apocalyptic space objects.

Independent astronomy software developer Bill Gray, who has been working to track the debris with Nasa’s Jet Propulsion Laboratory in Pasadena, California, told journal Nature: “I would not necessarily want to be going fishing directly underneath it.”