Asteroid impact avoidance comprises a number of methods by which
near-Earth objects (NEO) could be diverted, preventing destructive
impact events. A sufficiently large impact by an asteroid or other NEOs would cause, depending on its impact location, massive
tsunamis, multiple
firestorms and an
impact winter caused by the sunlight blocking effect of placing large quantities of pulverized rock dust, and other debris, into the
stratosphere.