“It Keeps Me up at Night”: NASA Warns Earth Is Threatened by 15,000 Asteroids Big Enough to Wipe Out a City

NASA warns that Earth faces a threat from nearly 15,000 undetected 'city-killer' asteroids larger than 140 meters, which remain unlocated despite existing in the solar system. These asteroids, capable of regional devastation, highlight a gap in current planetary defense capabilities. NASA's NEO Surveyor telescope, set to launch in late 2027, aims to close this detection gap, while the DART mission demonstrated the feasibility of asteroid deflection.