The idea of intentionally smashing a spacecraft into an asteroid may evoke memories of science fiction blockbusters such as Armageddon or Deep Impact. But it became a reality last week, as NASA's Double Asteroid Redirection Test (DART) spacecraft soared into a small asteroid called Dimorphos at 14,000mph, with the aim of tweaking its orbit. The space agency hopes the technology could one day be used to defend Earth against a'doomsday' asteroid or comet. But could we really avoid a future Armageddon if we detected a huge space rock headed our way? MailOnline's Executive Science and Technology Editor, Shivali Best, investigates.