Yes a killer asteroid could hit Earth

(Popular Science) - Earth is in a constant game of celestial bumper cars colliding withand obliteratingthe relatively puny space rocks that dare cross its path. The planet is still standing after 4.6 billion years but a modern collision could devastate cities continents and even life itself. (Just ask the ­dinosaurs.) NASAs Center for Near-Earth Object Studies keeps watch on more than 18000 potential troublemakers ranging from just 3 feet to more than 3000 feet across. Meteorites smaller than 100 feet usually ­explode in midair like one did over Chelyabinsk Russia in 2013. There wasnt enough shrapnel to leave a crater but the sonic boom did blast out windows. So how much havoc could larger rocks wreak? Read More