By Joey Roulette WASHINGTON (Reuters) – The discovery of an asteroid the size of a small shipping truck mere days before it passed Earth on Thursday, albeit one that posed no threat to humans, highlights a blind spot in our ability to predict those that could actually cause damage, astronomers say. NASA for years has prioritized detecting asteroids much bigger and more existentially threatening than 2023 BU, the small space rock that streaked by 2,200 miles from the Earth’s surface, closer than some satellites. If bound for Earth, it would have been pulverized in the atmosphere, with only smal…