But if it starts to, the European Space Agency will call Don Quixote to the rescue . . .
From Science Daily: ESA Selects Targets For Asteroid-deflecting Mission Don Quijote
Based on the recommendations of asteroid experts, ESA has selected two target asteroids for its Near-Earth Object deflecting mission, Don Quijote.
Don Quijote is an asteroid-deflecting mission currently under study by ESA’s Advanced Concepts Team (ACT). Earlier this year the NEO Mission Advisory Panel (NEOMAP), consisting of well-known experts in the field, delivered to ESA a target selection report for Europe’s future asteroid mitigation missions, identifying the relevant criteria for selecting a target and picking up two objects that meet most of those criteria. The asteroids’ temporary designations are 2002 AT4 and 1989 ML.