How does NASA stop asteroids from hitting Earth?

When NASA managed to smash a satellite into an asteroid last week, people across the world rejoiced that humanity could be saved if a huge space rock heads for earth. But will it really work if a planet-killing asteroid like the six-mile-wide one that wiped out the dinosaurs is about to hit our planet? How much notice will NASA scientists need? And will they need nuclear weapons. This is our video guide with the answers.
MailOnline's executive science and technology editor Shivali Best investigates how NASA redirects dangerous asteroids by deliberately crashing its DART (Double Asteroid Redirection Test) spacecraft to alter the asteroid's orbit.
#nasa #asteroid #science #technology #dailymail

[flawlesswill]

they dont and they havnt ever stopped a asteroid hitting earth so stupid question

[earthervsearther]

it's does not have to because there are no dangerous flying rocks and no evidence of them