keep an eye on the sky this thursday night… “asteroid YU55 orbits in a trajectory that regularly brings it close to earth, venus and mars, as it cruises our solar system. but, according to NASA, an asteroid has not been this close to earth in at least 200 years. at its closest approach, which was expected around 6:28 p.m. eastern time/3:28 p.m. pacific, it will be no closer than 201,700 miles (as measured from the center of the earth). that’s about 85 percent of the distance between earth and the moon. if you miss it tomorrow night you can keep an eye for its return orbit in 2028. the calculations suggest that an impact is not possible this time round but, in theory, the earth’s gravity will perturb the asteroid’s path, possibly leading to an impact in 2039. astronomers stress that a collision is only one of a range of possibilities for this kilometer-wide chunk of rock. if it did strike, it would cause continent-wide devastation and alter the earth’s climate beyond anything george w. bush could have ever done”. by cm