An asteroid is on a collision path with Earth and could hit the planet in 17 years. Astronomers initially spotted asteroid 2002 NT7 on July 5th, through the Linear Observatory's automated sky survey programme in New Mexico in the United States. Their initial calculation show it is due to hit our planet on February 1st, 2019.
Although more work needs to be done to pin down the asteroid's precise path, if the first fears prove true we have just 17 years to find a way to stop the 2 km-wide object causing global catastrophe.
Astronomers have given the object a rating on the so-called Palermo technical scale of threat of 0.06, making NT7 the first object to be given a positive value.
Astronomers across the world are keeping a close eye on the asteroid, which circles the sun every 837 days and travels in a tilted orbit from about the distance of Mars to just within Earth's orbit.
Dr Benny Peiser of Liverpool John Moores University told the BBC yesterday: "This unique event should not diminish the fact that additional observations in coming weeks will almost certainly - we hope - eliminate the current threat."
Dr Donald Yeomans, of NASA, said: "The orbit of this object is rather highly inclined to the Earth's orbit so it has been missed because until recently observers were not looking for such objects in that region of space"
Dr Peiser said: "Objects of this size only hit the Earth every one or two million years. In the worst-case scenario, a disaster of this size would be global in its extent, would create a meltdown of our economic and social life and would reduce us to dark age conditions."
At the moment, he added, scientists feared it could take at least 30 years to be able to devise and set up a mission to deal with such a threat - a timescale which would be woefully inadequate if the 2019 strike were to happen.