The fifth Planetary Defense Interagency Tabletop Exercise focused on an asteroid impact scenario designed by NASA JPL’s Center for Near Earth Object Studies. A large asteroid impacting Earth is highly unlikely for the foreseeable future. But because the damage from such an event could be great, NASA leads hypothetical asteroid impact “tabletop” exercises every two years with experts and decision-makers from federal and international agencies to address the many uncertainties of an impact scenario. The most recent exercise took place this past April, with a preliminary report being issued on Ju…