POTSDAM (Eastern Germany): Nico Marquardt, a 13-year-old school student, poses behind a model depicting Apophis, a near-earth asteroid, in relation to the orbit of the earth around the sun, at his school on Friday. Marquardt ‘corrected’ estimates prepared by the National Aeronautics and Space Administration on the chances of the asteroid colliding with earth by using telescopic findings from the Institute of Astrophysics in Potsdam. The Nasa, however, says that its figures are correct, not the boy’s. Marquardt had calculated there was a 1-in-450 chance that Apophis would collide with earth. He argued that Nasa scientists had got it wrong when they estimated the chances of a collision at only 1 in 45,000. “We stand by our numbers,” Nasa spokesman Dwayne Brown said on Wednesday.—AFP