This video lays out the real threat of asteroids to planet earth:
For more info see Asteroid Impacts.
The threat of an asteroid strike is real, and the potential for a life-ending event for the planet is a possibility. Humans have not yet mapped most of the asteroid threats the planet faces, and we do not yet have a defense system that could eliminate a threat even if we detected one. In other words, this doomsday scenario is a real threat that deserves real action.
“The Doomsday Book” by Marshall Brain lays out this scenario in amazing detail and offers solutions to prevent this doomsday scenario from unfolding. You can order the book today on Amazon and other retailers.