Nasa dismisses asteroid collision claim

The chances of a recently discovered mile-wide asteroid, forecast to hurtle towards Earth, actually hitting the planet are "minimal", a Nasa scientist said today.

But if it did, asteroid 2002 NT7 would strike on February 1 2019 unleashing tidal waves, massive fires, global volcanic activity and an electromagnetic pulse that would destroy most of the electronics on Earth.

Astronomers have given the object a 0.06 rating on the Palermo technical scale (a scale used to measure asteroid threats), making it the first to be given a positive value.

Initial calculations show that its 837-day course around the Sun - which tilts to just within the Earth's orbit - could put it on a collision course in less than 17 years.

Donald Yeomans of Nasa's jet propulsion laboratory said the margin of error was however tens of millions of miles, meaning the likely threat was minimal.

"An object of this size would be expected to hit the Earth every few million years, and as we get additional data I think this threat will go away," he told the BBC.

An asteroid that hit New Mexico 65m years ago is believed to have killed off the dinosaurs.

The Liberal Democrat MP Lembit Opik, who campaigns for the government to take asteroid threats seriously, said 2002 NT7 was the most dangerous object yet seen in space.

"There's a good chance this particular object won't hit us but we know that a large object will hit us sooner or later. This is the closest approach we have seen so far," he said.

"It does sound like a science fiction story and I may sound like one of these guys who walks up and down with a sandwich board saying the end of the world is nigh, but the end is nigh."

Last month an asteroid the size of a football pitch missed the Earth by 75,000 miles - less than one-third of the distance to the moon. It was not observed until three days later.

Scientists said if it had hit a populated area, it would have released as much energy as a large nuclear weapon.