How NASA plans to knock asteroids heading toward Earth off course

Since one of the biggest asteroids to strike Earth nearly 65 million years ago, our planet has been unarmed — until now.
On the front lines of defending the planet is the newest technological advancement by NASA’s Planetary Defense team: the Double Asteroid Redirection Test, otherwise known as DART.
DART’s mission? To knock asteroids flying close to Earth off-course by striking them at a speed about nine times faster than a bullet.
NASA plans on testing the DART system on the