Could We Spot a Doomsday Asteroid Before It Strikes?

The article asks if humanity could detect an extinction-level asteroid before impact, using the dinosaurs’ 10 km carbonaceous impactor as a case study. It explains that warning time depends on the object’s origin, speed (~21 km/s), and whether it brightens from outgassing; best-case scenarios could offer weeks to a month of naked-eye visibility if the body comes from the night side and becomes bright, but more typical cases might yield only days or hours, or no warning at all if it’s sun-ward or depleted of volatiles. It also highlights how albedo and orbital geometry affect detectability, and stresses the need for planetary defense to gain decades of lead time for meaningful intervention.