NASA says it can’t afford to build a space telescope considered the fastest way to identify asteroids that might impact the Earth with terrible consequences. A 2015 law gave the space agency five years to identify 90% of near-Earth objects larger than 140 meters in diameter, which could devastate cities, regions and even civilization itself if they were to impact the planet. NASA isn’t going to meet that deadline, and scientists believe they have so far only identified about a third of the asteroids considered a threat.