“Asteroid 1999 RQ36, which has a one-in-1,000 chance of hitting the Earth before the year 2200, would cause an explosion equivalent to hundreds of nuclear bombs detonating at once.   An analysis of its orbit has predicted that it is most likely to hit us on September 24, 2182 but scientists want to collect a sample of the rock to help forecast its trajectory more accurately.   Space mission to explore asteroids If Nasa gives the plan the green light, the spacecraft would blast off in 2106 to map out and collect rock samples from the asteroid, which is 1,800 feet-wide.   The planned mission, called OSIRIS-Rex, is one of three finalists in competition for funding as part of the cash-strapped US space agency’s New Frontiers program.   The other contenders are missions to the Moon and to Venus respectively and the winner will be announced next year.   Plans to land an astronaut on an asteroid will come under discussion at a two-day Nasa workshop in Washington DC…   Nasa has officially classified RQ36 as a ‘potentially hazardous asteroid’ as it passes within about 280,000 miles of Earth. Its orbit, which brings it closer to Earth, makes it easier to reach than other asteroids.   Michael Drake, who would lead the OSIRIS-Rex team if the project was chosen, said: ‘Being one of the easiest targets to get to coincidentally means that it also can easily hit us, too’ “

Clark Chapman, a planetary scientist at Southwest Research Institute in Boulder, Colorado, said an impact from RQ36 would cause a catastrophic explosion.

“It would be an enormous impact, like hundreds of the biggest nuclear bombs ever built exploding at once, creating a crater maybe 10 kilometers across,” he told National Geographic magazine.

An expert panel appointed by Barack Obama, the US president, to assess Nasa’s future space programme last year recommended bypassing the Moon in favour of a mission to land on an unidentified asteroid.

The plan mirrors the plot of the 1998 Hollywood film Deep Impact, in which the White House sends a spaceship to land on an asteroid which is hurtling towards the Earth.

“A giant asteroid could be on course to hit Earth causing massive devastation, space boffins revealed today.  An international team including NASA experts warned a 560m wide space rock has been discovered heading this way.  If it did hit Earth it would blast a crater several miles wide and could devastate a city the size of London, wreaking death and destruction for hundreds of miles in every direction.  Anyone concerned by the warning has one thing to be thankful for — if it does hit it is most likely to happen in 2182.  That gives scientists 172 years to work out how to deal with it.  The asteroid was discovered in 1999 and is dubbed 1999 RQ36.  The scientists had labelled it a ‘potentially hazardous asteroid’ of the Apollo group because its orbit brings it close to Earth.  But it was then considered a much lower risk!”