The crater, on its own, is a poor guide. The real action, geophysicists argue, happens in the air and in the first heartbeat after impact, when rock, metal and vapor ignore the neat circle journalists love to photograph.
Most incoming bodies never reach the ground intact. Supersonic entry drives extreme aerodynamic pressure, forcing meteoroids to fragment in the upper atmosphere; that breakup, described by shock loading and dynamic pressure, sprays pieces along the flight path so they fall in long, narrow strewn fields well beyond any later crater. Some fragments decelerate to terminal velocity and simply rain down, while denser cores keep far more momentum, skipping over the final blast site like shrapnel from an artillery shell.
Even when a solid impactor does punch through, the crater rim still lies to one side of the story. Hypervelocity impact generates a transient cavity and an ejecta curtain, governed by ballistic trajectories and conservation of momentum, that lofts target rock and bits of the impactor on steep, asymmetric arcs. Local winds, entry angle and rotation of the planet then shear that curtain into downrange fans that can stretch for kilometers. What looks, from orbit, like a simple bowl is in practice the quiet center of a much wider, hidden field of debris.
